BASELINE: Update Chromium to 85.0.4183.14085-based

Change-Id: Iaa42f4680837c57725b1344f108c0196741f6057
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

74 files changed, 4082 insertions, 453 deletions

diff --git a/chromium/v8/tools/clusterfuzz/v8_commands.py b/chromium/v8/tools/clusterfuzz/v8_commands.py
index 1956ef2802b..58a757e7a79 100644
--- a/chromium/v8/tools/clusterfuzz/v8_commands.py
+++ b/chromium/v8/tools/clusterfuzz/v8_commands.py
@@ -40,9 +40,6 @@ JS_SUPPRESSIONS = os.path.join(BASE_PATH, 'v8_suppressions.js')
 ARCH_MOCKS = os.path.join(BASE_PATH, 'v8_mock_archs.js')
 WEBASSEMBLY_MOCKS = os.path.join(BASE_PATH, 'v8_mock_webassembly.js')
 
-# Timeout in seconds for one d8 run.
-TIMEOUT = 3
-
 
 def _startup_files(options):
   """Default files and optional config-specific mock files."""
@@ -70,7 +67,7 @@ class Command(object):
 
     self.files = _startup_files(options)
 
-  def run(self, testcase, verbose=False):
+  def run(self, testcase, timeout, verbose=False):
     """Run the executable with a specific testcase."""
     args = [self.executable] + self.flags + self.files + [testcase]
     if verbose:
@@ -82,7 +79,7 @@ class Command(object):
     return Execute(
         args,
         cwd=os.path.dirname(os.path.abspath(testcase)),
-        timeout=TIMEOUT,
+        timeout=timeout,
     )
 
   @property
diff --git a/chromium/v8/tools/clusterfuzz/v8_foozzie.py b/chromium/v8/tools/clusterfuzz/v8_foozzie.py
index b6638cc3774..b3cb8cf94fa 100755
--- a/chromium/v8/tools/clusterfuzz/v8_foozzie.py
+++ b/chromium/v8/tools/clusterfuzz/v8_foozzie.py
@@ -94,6 +94,10 @@ RETURN_FAIL = 2
 BASE_PATH = os.path.dirname(os.path.abspath(__file__))
 SANITY_CHECKS = os.path.join(BASE_PATH, 'v8_sanity_checks.js')
 
+# Timeout for one d8 run.
+SANITY_CHECK_TIMEOUT_SEC = 1
+TEST_TIMEOUT_SEC = 3
+
 SUPPORTED_ARCHS = ['ia32', 'x64', 'arm', 'arm64']
 
 # Output for suppressed failure case.
@@ -143,6 +147,25 @@ ORIGINAL_SOURCE_HASH_LENGTH = 3
 # Placeholder string if no original source file could be determined.
 ORIGINAL_SOURCE_DEFAULT = 'none'
 
+# Placeholder string for failures from crash tests. If a failure is found with
+# this signature, the matching sources should be moved to the mapping below.
+ORIGINAL_SOURCE_CRASHTESTS = 'placeholder for CrashTests'
+
+# Mapping from relative original source path (e.g. CrashTests/path/to/file.js)
+# to a string key. Map to the same key for duplicate issues. The key should
+# have more than 3 characters to not collide with other existing hashes.
+# If a symptom from a particular original source file is known to map to a
+# known failure, it can be added to this mapping. This should be done for all
+# failures from CrashTests, as those by default map to the placeholder above.
+KNOWN_FAILURES = {
+  # Foo.caller with asm.js: https://crbug.com/1042556
+  'CrashTests/5712410200899584/04483.js': '.caller',
+  'CrashTests/5703451898085376/02176.js': '.caller',
+  'CrashTests/4846282433495040/04342.js': '.caller',
+  # Flaky issue that almost never repros.
+  'CrashTests/5694376231632896/1033966.js': 'flaky',
+}
+
 
 def infer_arch(d8):
   """Infer the V8 architecture from the build configuration next to the
@@ -229,7 +252,7 @@ def parse_args():
   options.first = first_config_arguments.make_options(options)
   options.second = second_config_arguments.make_options(options)
 
-  # Ensure we make a sane comparison.
+  # Ensure we make a valid comparison.
   if (options.first.d8 == options.second.d8 and
       options.first.config == options.second.config):
     parser.error('Need either executable or config difference.')
@@ -292,6 +315,7 @@ def print_difference(
   else:
     first_stdout = first_config_output.stdout.decode('utf-8', 'replace')
     second_stdout = second_config_output.stdout.decode('utf-8', 'replace')
+    difference = difference.decode('utf-8', 'replace')
 
   text = (FAILURE_TEMPLATE % dict(
       configs='%s:%s' % (first_config_label, second_config_label),
@@ -313,6 +337,31 @@ def print_difference(
     print(text.encode('utf-8', 'replace'))
 
 
+def cluster_failures(source, known_failures=None):
+  """Returns a string key for clustering duplicate failures.
+
+  Args:
+    source: The original source path where the failure happened.
+    known_failures: Mapping from original source path to failure key.
+  """
+  known_failures = known_failures or KNOWN_FAILURES
+  # No source known. Typical for manually uploaded issues. This
+  # requires also manual issue creation.
+  if not source:
+    return ORIGINAL_SOURCE_DEFAULT
+  # Source is known to produce a particular failure.
+  if source in known_failures:
+    return known_failures[source]
+  # Subsume all other sources from CrashTests under one key. Otherwise
+  # failures lead to new crash tests which in turn lead to new failures.
+  if source.startswith('CrashTests'):
+    return ORIGINAL_SOURCE_CRASHTESTS
+
+  # We map all remaining failures to a short hash of the original source.
+  long_key = hashlib.sha1(source.encode('utf-8')).hexdigest()
+  return long_key[:ORIGINAL_SOURCE_HASH_LENGTH]
+
+
 def main():
   options = parse_args()
 
@@ -342,8 +391,20 @@ def main():
   # Sanity checks. Run both configurations with the sanity-checks file only and
   # bail out early if different.
   if not options.skip_sanity_checks:
-    first_config_output = first_cmd.run(SANITY_CHECKS)
-    second_config_output = second_cmd.run(SANITY_CHECKS)
+    first_config_output = first_cmd.run(
+        SANITY_CHECKS, timeout=SANITY_CHECK_TIMEOUT_SEC)
+
+    # Early bailout if first run was a timeout.
+    if timeout_bailout(first_config_output, 1):
+      return RETURN_PASS
+
+    second_config_output = second_cmd.run(
+        SANITY_CHECKS, timeout=SANITY_CHECK_TIMEOUT_SEC)
+
+    # Bailout if second run was a timeout.
+    if timeout_bailout(second_config_output, 2):
+      return RETURN_PASS
+
     difference, _ = suppress.diff(first_config_output, second_config_output)
     if difference:
       # Special source key for sanity checks so that clusterfuzz dedupes all
@@ -354,13 +415,15 @@ def main():
           first_config_output, second_config_output, difference)
       return RETURN_FAIL
 
-  first_config_output = first_cmd.run(options.testcase, verbose=True)
+  first_config_output = first_cmd.run(
+      options.testcase, timeout=TEST_TIMEOUT_SEC, verbose=True)
 
   # Early bailout if first run was a timeout.
   if timeout_bailout(first_config_output, 1):
     return RETURN_PASS
 
-  second_config_output = second_cmd.run(options.testcase, verbose=True)
+  second_config_output = second_cmd.run(
+      options.testcase, timeout=TEST_TIMEOUT_SEC, verbose=True)
 
   # Bailout if second run was a timeout.
   if timeout_bailout(second_config_output, 2):
@@ -368,12 +431,6 @@ def main():
 
   difference, source = suppress.diff(first_config_output, second_config_output)
 
-  if source:
-    long_key = hashlib.sha1(source.encode('utf-8')).hexdigest()
-    source_key = long_key[:ORIGINAL_SOURCE_HASH_LENGTH]
-  else:
-    source_key = ORIGINAL_SOURCE_DEFAULT
-
   if difference:
     # Only bail out due to suppressed output if there was a difference. If a
     # suppression doesn't show up anymore in the statistics, we might want to
@@ -383,6 +440,7 @@ def main():
     if fail_bailout(second_config_output, suppress.ignore_by_output2):
       return RETURN_FAIL
 
+    source_key = cluster_failures(source)
     print_difference(
         options, source_key, first_cmd, second_cmd,
         first_config_output, second_config_output, difference, source)
diff --git a/chromium/v8/tools/clusterfuzz/v8_foozzie_test.py b/chromium/v8/tools/clusterfuzz/v8_foozzie_test.py
index f82afc9e205..4a5affd76ea 100755
--- a/chromium/v8/tools/clusterfuzz/v8_foozzie_test.py
+++ b/chromium/v8/tools/clusterfuzz/v8_foozzie_test.py
@@ -51,8 +51,8 @@ class ConfigTest(unittest.TestCase):
     assert all(map(lambda x: x[3] in KNOWN_BUILDS, EXPERIMENTS))
     # Ensure we compare different configs and same d8, or same config
     # to different d8.
-    is_sane_comparison = lambda x: (x[1] == x[2]) == ('d8' != x[3])
-    assert all(map(is_sane_comparison, EXPERIMENTS))
+    is_valid_comparison = lambda x: (x[1] == x[2]) == ('d8' != x[3])
+    assert all(map(is_valid_comparison, EXPERIMENTS))
     # All flags have a probability.
     first_is_float = lambda x: type(x[0]) == float
     assert all(map(first_is_float, FLAGS))
@@ -101,6 +101,23 @@ class ConfigTest(unittest.TestCase):
 
 
 class UnitTest(unittest.TestCase):
+  def testCluster(self):
+    crash_test_example_path = 'CrashTests/path/to/file.js'
+    self.assertEqual(
+        v8_foozzie.ORIGINAL_SOURCE_DEFAULT,
+        v8_foozzie.cluster_failures(''))
+    self.assertEqual(
+        v8_foozzie.ORIGINAL_SOURCE_CRASHTESTS,
+        v8_foozzie.cluster_failures(crash_test_example_path))
+    self.assertEqual(
+        '_o_O_',
+        v8_foozzie.cluster_failures(
+            crash_test_example_path,
+            known_failures={crash_test_example_path: '_o_O_'}))
+    self.assertEqual(
+        '980',
+        v8_foozzie.cluster_failures('v8/test/mjsunit/apply.js'))
+
   def testDiff(self):
     def diff_fun(one, two, skip=False):
       suppress = v8_suppressions.get_suppression(
diff --git a/chromium/v8/tools/clusterfuzz/v8_mock.js b/chromium/v8/tools/clusterfuzz/v8_mock.js
index 6372a7afe2b..ca1336a0df6 100644
--- a/chromium/v8/tools/clusterfuzz/v8_mock.js
+++ b/chromium/v8/tools/clusterfuzz/v8_mock.js
@@ -149,6 +149,20 @@ Object.defineProperty(
   Float64Array = mock(Float64Array);
 })();
 
+// Mock buffer access via DataViews because of varying NaN patterns.
+(function() {
+  const origIsNaN = isNaN;
+  const deNaNify = function(value) { return origIsNaN(value) ? 1 : value; };
+  const origSetFloat32 = DataView.prototype.setFloat32;
+  DataView.prototype.setFloat32 = function(offset, value, ...rest) {
+    origSetFloat32.call(this, offset, deNaNify(value), ...rest);
+  };
+  const origSetFloat64 = DataView.prototype.setFloat64;
+  DataView.prototype.setFloat64 = function(offset, value, ...rest) {
+    origSetFloat64.call(this, offset, deNaNify(value), ...rest);
+  };
+})();
+
 // Mock Worker.
 (function() {
   let index = 0;
diff --git a/chromium/v8/tools/debug_helper/BUILD.gn b/chromium/v8/tools/debug_helper/BUILD.gn
index a2d76d1fda7..522a0e22702 100644
--- a/chromium/v8/tools/debug_helper/BUILD.gn
+++ b/chromium/v8/tools/debug_helper/BUILD.gn
@@ -76,6 +76,7 @@ v8_component("v8_debug_helper") {
     "$target_gen_dir/../../torque-generated/class-debug-readers-tq.h",
     "$target_gen_dir/../../torque-generated/instance-types-tq.h",
     "$target_gen_dir/heap-constants-gen.cc",
+    "compiler-types.cc",
     "debug-helper-internal.cc",
     "debug-helper-internal.h",
     "debug-helper.h",
diff --git a/chromium/v8/tools/debug_helper/compiler-types.cc b/chromium/v8/tools/debug_helper/compiler-types.cc
new file mode 100644
index 00000000000..1d9f6eb0d3e
--- /dev/null
+++ b/chromium/v8/tools/debug_helper/compiler-types.cc
@@ -0,0 +1,31 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "debug-helper-internal.h"
+#include "src/compiler/types.h"
+
+namespace ic = v8::internal::compiler;
+
+extern "C" {
+V8_DEBUG_HELPER_EXPORT const char* _v8_debug_helper_BitsetName(
+    uint64_t payload) {
+  // Check if payload is a bitset and return the bitset type.
+  // This line is duplicating the logic from Type::IsBitset.
+  bool is_bit_set = payload & 1;
+  if (!is_bit_set) return nullptr;
+  ic::BitsetType::bitset bits =
+      static_cast<ic::BitsetType::bitset>(payload ^ 1u);
+  switch (bits) {
+#define RETURN_NAMED_TYPE(type, value) \
+  case ic::BitsetType::k##type:        \
+    return #type;
+    PROPER_BITSET_TYPE_LIST(RETURN_NAMED_TYPE)
+    INTERNAL_BITSET_TYPE_LIST(RETURN_NAMED_TYPE)
+#undef RETURN_NAMED_TYPE
+
+    default:
+      return nullptr;
+  }
+}
+}
diff --git a/chromium/v8/tools/debug_helper/debug-helper.h b/chromium/v8/tools/debug_helper/debug-helper.h
index df850e81edb..dc08bf63469 100644
--- a/chromium/v8/tools/debug_helper/debug-helper.h
+++ b/chromium/v8/tools/debug_helper/debug-helper.h
@@ -195,6 +195,8 @@ V8_DEBUG_HELPER_EXPORT void _v8_debug_helper_Free_ObjectPropertiesResult(
     v8::debug_helper::ObjectPropertiesResult* result);
 V8_DEBUG_HELPER_EXPORT const v8::debug_helper::ClassList*
 _v8_debug_helper_ListObjectClasses();
+V8_DEBUG_HELPER_EXPORT const char* _v8_debug_helper_BitsetName(
+    uint64_t payload);
 }
 
 namespace v8 {
@@ -229,6 +231,12 @@ inline const ClassList* ListObjectClasses() {
   return _v8_debug_helper_ListObjectClasses();
 }
 
+// Return a bitset name for a v8::internal::compiler::Type with payload or null
+// if the payload is not a bitset.
+inline const char* BitsetName(uint64_t payload) {
+  return _v8_debug_helper_BitsetName(payload);
+}
+
 }  // namespace debug_helper
 }  // namespace v8
 
diff --git a/chromium/v8/tools/dev/gm.py b/chromium/v8/tools/dev/gm.py
index 9d5cbf056a2..f1c2f1fabc9 100755
--- a/chromium/v8/tools/dev/gm.py
+++ b/chromium/v8/tools/dev/gm.py
@@ -10,12 +10,15 @@ Uses Goma by default if it is detected (at output directory setup time).
 Expects to be run from the root of a V8 checkout.
 
 Usage:
-    gm.py [<arch>].[<mode>[-<suffix>]].[<target>] [testname...]
+    gm.py [<arch>].[<mode>[-<suffix>]].[<target>] [testname...] [--flag]
 
 All arguments are optional. Most combinations should work, e.g.:
     gm.py ia32.debug x64.release x64.release-my-custom-opts d8
-    gm.py android_arm.release.check
+    gm.py android_arm.release.check --progress=verbose
     gm.py x64 mjsunit/foo cctest/test-bar/*
+
+Flags are passed unchanged to the test runner. They must start with -- and must
+not contain spaces.
 """
 # See HELP below for additional documentation.
 # Note on Python3 compatibility: gm.py itself is Python3 compatible, but
@@ -170,14 +173,14 @@ def _CallWithOutput(cmd):
   print("# %s" % cmd)
   # The following trickery is required so that the 'cmd' thinks it's running
   # in a real terminal, while this script gets to intercept its output.
-  master, slave = pty.openpty()
-  p = subprocess.Popen(cmd, shell=True, stdin=slave, stdout=slave, stderr=slave)
-  os.close(slave)
+  parent, child = pty.openpty()
+  p = subprocess.Popen(cmd, shell=True, stdin=child, stdout=child, stderr=child)
+  os.close(child)
   output = []
   try:
     while True:
       try:
-        data = os.read(master, 512).decode('utf-8')
+        data = os.read(parent, 512).decode('utf-8')
       except OSError as e:
         if e.errno != errno.EIO: raise
         break # EIO means EOF on some systems
@@ -188,7 +191,7 @@ def _CallWithOutput(cmd):
         sys.stdout.flush()
         output.append(data)
   finally:
-    os.close(master)
+    os.close(parent)
     p.wait()
   return p.returncode, "".join(output)
 
@@ -224,11 +227,12 @@ def PrepareMksnapshotCmdline(orig_cmdline, path):
   return result
 
 class Config(object):
-  def __init__(self, arch, mode, targets, tests=[]):
+  def __init__(self, arch, mode, targets, tests=[], testrunner_args=[]):
     self.arch = arch
     self.mode = mode
     self.targets = set(targets)
     self.tests = set(tests)
+    self.testrunner_args = testrunner_args
 
   def Extend(self, targets, tests=[]):
     self.targets.update(targets)
@@ -303,7 +307,9 @@ class Config(object):
       tests = " ".join(self.tests)
     return _Call('"%s" ' % sys.executable +
                  os.path.join("tools", "run-tests.py") +
-                 " --outdir=%s %s" % (GetPath(self.arch, self.mode), tests))
+                 " --outdir=%s %s %s" % (
+                     GetPath(self.arch, self.mode), tests,
+                     " ".join(self.testrunner_args)))
 
 def GetTestBinary(argstring):
   for suite in TESTSUITES_TARGETS:
@@ -316,13 +322,15 @@ class ArgumentParser(object):
     self.global_tests = set()
     self.global_actions = set()
     self.configs = {}
+    self.testrunner_args = []
 
   def PopulateConfigs(self, arches, modes, targets, tests):
     for a in arches:
       for m in modes:
         path = GetPath(a, m)
         if path not in self.configs:
-          self.configs[path] = Config(a, m, targets, tests)
+          self.configs[path] = Config(a, m, targets, tests,
+                  self.testrunner_args)
         else:
           self.configs[path].Extend(targets, tests)
 
@@ -348,6 +356,10 @@ class ArgumentParser(object):
     # tests have names like "S15.4.4.7_A4_T1", don't split these.
     if argstring.startswith("unittests/") or argstring.startswith("test262/"):
       words = [argstring]
+    elif argstring.startswith("--"):
+      # Pass all other flags to test runner.
+      self.testrunner_args.append(argstring)
+      return
     else:
       # Assume it's a word like "x64.release" -> split at the dot.
       words = argstring.split('.')
diff --git a/chromium/v8/tools/gcmole/BUILD.gn b/chromium/v8/tools/gcmole/BUILD.gn
index fc7d81e561d..9767acbf5a1 100644
--- a/chromium/v8/tools/gcmole/BUILD.gn
+++ b/chromium/v8/tools/gcmole/BUILD.gn
@@ -16,6 +16,7 @@ group("v8_run_gcmole") {
     "parallel.py",
     "run-gcmole.py",
     "suspects.whitelist",
+    "ignored_files",
     "test-expectations.txt",
 
     # The following contains all relevant source and build files.
@@ -37,9 +38,7 @@ group("v8_run_gcmole") {
     "$target_gen_dir/../../torque-generated/",
   ]
 
-  deps = [
-    "../../:run_torque",
-  ]
+  deps = [ "../../:run_torque" ]
 
   if (v8_gcmole) {
     # This assumes gcmole tools have been fetched by a hook
diff --git a/chromium/v8/tools/gcmole/gcmole-test.cc b/chromium/v8/tools/gcmole/gcmole-test.cc
index e0e2801f777..92f7a9eda88 100644
--- a/chromium/v8/tools/gcmole/gcmole-test.cc
+++ b/chromium/v8/tools/gcmole/gcmole-test.cc
@@ -189,7 +189,7 @@ void TestGuardedDeadVarAnalysisNotOnStack(Isolate* isolate) {
 void TestGuardedDeadVarAnalysisNested(JSObject raw_obj, Isolate* isolate) {
   CauseGCRaw(raw_obj, isolate);
 
-  // Shouldn't cause warning.
+  // Should cause warning.
   raw_obj.Print();
 }
 
@@ -198,6 +198,9 @@ void TestGuardedDeadVarAnalysisCaller(Isolate* isolate) {
   JSObject raw_obj = *isolate->factory()->NewJSObjectWithNullProto();
 
   TestGuardedDeadVarAnalysisNested(raw_obj, isolate);
+
+  // Shouldn't cause warning.
+  raw_obj.Print();
 }
 
 JSObject GuardedAllocation(Isolate* isolate) {
diff --git a/chromium/v8/tools/gcmole/gcmole-tools.tar.gz.sha1 b/chromium/v8/tools/gcmole/gcmole-tools.tar.gz.sha1
index 8f7876fa519..221e2e9d293 100644
--- a/chromium/v8/tools/gcmole/gcmole-tools.tar.gz.sha1
+++ b/chromium/v8/tools/gcmole/gcmole-tools.tar.gz.sha1
@@ -1 +1 @@
-d2f949820bf1ee7343a7b5f46987a3657aaea2e9
\ No newline at end of file
+0af04ef475bc746a501fe17d3b56ccb03fc151fc
diff --git a/chromium/v8/tools/gcmole/gcmole.cc b/chromium/v8/tools/gcmole/gcmole.cc
index 606c90bb582..cce177caf9e 100644
--- a/chromium/v8/tools/gcmole/gcmole.cc
+++ b/chromium/v8/tools/gcmole/gcmole.cc
@@ -46,6 +46,7 @@
 namespace {
 
 bool g_tracing_enabled = false;
+bool g_dead_vars_analysis = false;
 
 #define TRACE(str)                   \
   do {                               \
@@ -61,12 +62,14 @@ bool g_tracing_enabled = false;
     }                                                             \
   } while (false)
 
-#define TRACE_LLVM_DECL(str, decl)   \
-  do {                               \
-    if (g_tracing_enabled) {         \
-      std::cout << str << std::endl; \
-      decl->dump();                  \
-    }                                \
+// Node: The following is used when tracing --dead-vars
+// to provide extra info for the GC suspect.
+#define TRACE_LLVM_DECL(str, decl)                   \
+  do {                                               \
+    if (g_tracing_enabled && g_dead_vars_analysis) { \
+      std::cout << str << std::endl;                 \
+      decl->dump();                                  \
+    }                                                \
   } while (false)
 
 typedef std::string MangledName;
@@ -365,6 +368,11 @@ static bool KnownToCauseGC(clang::MangleContext* ctx,
 
   if (!InV8Namespace(decl)) return false;
 
+  if (suspects_whitelist.find(decl->getNameAsString()) !=
+      suspects_whitelist.end()) {
+    return false;
+  }
+
   MangledName name;
   if (GetMangledName(ctx, decl, &name)) {
     return gc_suspects.find(name) != gc_suspects.end();
@@ -387,6 +395,7 @@ static bool SuspectedToCauseGC(clang::MangleContext* ctx,
   }
 
   if (gc_functions.find(decl->getNameAsString()) != gc_functions.end()) {
+    TRACE_LLVM_DECL("Suspected by ", decl);
     return true;
   }
 
@@ -677,8 +686,7 @@ class FunctionAnalyzer {
                    clang::CXXRecordDecl* smi_decl,
                    clang::CXXRecordDecl* no_gc_decl,
                    clang::CXXRecordDecl* no_heap_access_decl,
-                   clang::DiagnosticsEngine& d, clang::SourceManager& sm,
-                   bool dead_vars_analysis)
+                   clang::DiagnosticsEngine& d, clang::SourceManager& sm)
       : ctx_(ctx),
         object_decl_(object_decl),
         maybe_object_decl_(maybe_object_decl),
@@ -687,8 +695,7 @@ class FunctionAnalyzer {
         no_heap_access_decl_(no_heap_access_decl),
         d_(d),
         sm_(sm),
-        block_(NULL),
-        dead_vars_analysis_(dead_vars_analysis) {}
+        block_(NULL) {}
 
   // --------------------------------------------------------------------------
   // Expressions
@@ -984,7 +991,7 @@ class FunctionAnalyzer {
       // pointers produces too many false positives in the dead variable
       // analysis.
       if (IsInternalPointerType(var_type) && !env.IsAlive(var_name) &&
-          !HasActiveGuard() && dead_vars_analysis_) {
+          !HasActiveGuard() && g_dead_vars_analysis) {
         ReportUnsafe(parent, DEAD_VAR_MSG);
       }
       return ExprEffect::RawUse();
@@ -1356,15 +1363,6 @@ class FunctionAnalyzer {
   }
 
   bool IsInternalPointerType(clang::QualType qtype) {
-    // Not yet assigned pointers can't get moved by the GC.
-    if (qtype.isNull()) {
-      return false;
-    }
-    // nullptr can't get moved by the GC.
-    if (qtype->isNullPtrType()) {
-      return false;
-    }
-
     const clang::CXXRecordDecl* record = qtype->getAsCXXRecordDecl();
     bool result = IsDerivedFromInternalPointer(record);
     TRACE_LLVM_TYPE("is internal " << result, qtype);
@@ -1374,6 +1372,15 @@ class FunctionAnalyzer {
   // Returns weather the given type is a raw pointer or a wrapper around
   // such. For V8 that means Object and MaybeObject instances.
   bool RepresentsRawPointerType(clang::QualType qtype) {
+    // Not yet assigned pointers can't get moved by the GC.
+    if (qtype.isNull()) {
+      return false;
+    }
+    // nullptr can't get moved by the GC.
+    if (qtype->isNullPtrType()) {
+      return false;
+    }
+
     const clang::PointerType* pointer_type =
         llvm::dyn_cast_or_null<clang::PointerType>(qtype.getTypePtrOrNull());
     if (pointer_type != NULL) {
@@ -1490,7 +1497,6 @@ class FunctionAnalyzer {
   clang::SourceManager& sm_;
 
   Block* block_;
-  bool dead_vars_analysis_;
 
   struct GCGuard {
     clang::CompoundStmt* stmt = NULL;
@@ -1507,10 +1513,10 @@ class ProblemsFinder : public clang::ASTConsumer,
  public:
   ProblemsFinder(clang::DiagnosticsEngine& d, clang::SourceManager& sm,
                  const std::vector<std::string>& args)
-      : d_(d), sm_(sm), dead_vars_analysis_(false) {
+      : d_(d), sm_(sm) {
     for (unsigned i = 0; i < args.size(); ++i) {
       if (args[i] == "--dead-vars") {
-        dead_vars_analysis_ = true;
+        g_dead_vars_analysis = true;
       }
       if (args[i] == "--verbose") {
         g_tracing_enabled = true;
@@ -1518,7 +1524,29 @@ class ProblemsFinder : public clang::ASTConsumer,
     }
   }
 
+  bool TranslationUnitIgnored() {
+    if (!ignored_files_loaded_) {
+      std::ifstream fin("tools/gcmole/ignored_files");
+      std::string s;
+      while (fin >> s) ignored_files_.insert(s);
+      ignored_files_loaded_ = true;
+    }
+
+    clang::FileID main_file_id = sm_.getMainFileID();
+    std::string filename = sm_.getFileEntryForID(main_file_id)->getName().str();
+
+    bool result = ignored_files_.find(filename) != ignored_files_.end();
+    if (result) {
+      llvm::outs() << "Ignoring file " << filename << "\n";
+    }
+    return result;
+  }
+
   virtual void HandleTranslationUnit(clang::ASTContext &ctx) {
+    if (TranslationUnitIgnored()) {
+      return;
+    }
+
     Resolver r(ctx);
 
     // It is a valid situation that no_gc_decl == NULL when the
@@ -1558,10 +1586,10 @@ class ProblemsFinder : public clang::ASTConsumer,
       no_heap_access_decl = no_heap_access_decl->getDefinition();
 
     if (object_decl != NULL && smi_decl != NULL && maybe_object_decl != NULL) {
-      function_analyzer_ = new FunctionAnalyzer(
-          clang::ItaniumMangleContext::create(ctx, d_), object_decl,
-          maybe_object_decl, smi_decl, no_gc_decl, no_heap_access_decl, d_, sm_,
-          dead_vars_analysis_);
+      function_analyzer_ =
+          new FunctionAnalyzer(clang::ItaniumMangleContext::create(ctx, d_),
+                               object_decl, maybe_object_decl, smi_decl,
+                               no_gc_decl, no_heap_access_decl, d_, sm_);
       TraverseDecl(ctx.getTranslationUnitDecl());
     } else {
       if (object_decl == NULL) {
@@ -1594,7 +1622,9 @@ class ProblemsFinder : public clang::ASTConsumer,
  private:
   clang::DiagnosticsEngine& d_;
   clang::SourceManager& sm_;
-  bool dead_vars_analysis_;
+
+  bool ignored_files_loaded_ = false;
+  std::set<std::string> ignored_files_;
 
   FunctionAnalyzer* function_analyzer_;
 };
diff --git a/chromium/v8/tools/gcmole/gcmole.lua b/chromium/v8/tools/gcmole/gcmole.lua
index a09c3b61ad5..95ba0433516 100644
--- a/chromium/v8/tools/gcmole/gcmole.lua
+++ b/chromium/v8/tools/gcmole/gcmole.lua
@@ -40,9 +40,8 @@ local FLAGS = {
    -- Print commands to console before executing them.
    verbose = false;
 
-   -- Perform dead variable analysis (generates many false positives).
-   -- TODO add some sort of whiteliste to filter out false positives.
-   dead_vars = false;
+   -- Perform dead variable analysis.
+   dead_vars = true;
 
    -- Enable verbose tracing from the plugin itself.
    verbose_trace = false;
@@ -322,6 +321,7 @@ local WHITELIST = {
 
    -- CodeCreateEvent receives AbstractCode (a raw ptr) as an argument.
    "CodeCreateEvent",
+   "WriteField",
 };
 
 local function AddCause(name, cause)
@@ -477,6 +477,17 @@ local function SafeCheckCorrectnessForArch(arch, for_test)
    return errors, output
 end
 
+-- Source: https://stackoverflow.com/a/41515925/1540248
+local function StringDifference(str1,str2)
+   for i = 1,#str1 do -- Loop over strings
+         -- If that character is not equal to its counterpart
+         if str1:sub(i,i) ~= str2:sub(i,i) then
+            return i --Return that index
+         end
+   end
+   return #str1+1 -- Return the index after where the shorter one ends as fallback.
+end
+
 local function TestRun()
    local errors, output = SafeCheckCorrectnessForArch('x64', true)
    if not errors then
@@ -491,6 +502,16 @@ local function TestRun()
 
    if output ~= expectations then
       log("** Output mismatch from running tests. Please run them manually.")
+      local idx = StringDifference(output, expectations)
+
+      log("Difference at byte "..idx)
+      log("Expected: "..expectations:sub(idx-10,idx+10))
+      log("Actual: "..output:sub(idx-10,idx+10))
+
+      log("--- Full output ---")
+      log(output)
+      log("------")
+
       return false
    end
 
diff --git a/chromium/v8/tools/gcmole/ignored_files b/chromium/v8/tools/gcmole/ignored_files
new file mode 100644
index 00000000000..05fcd7a129e
--- /dev/null
+++ b/chromium/v8/tools/gcmole/ignored_files
@@ -0,0 +1,2 @@
+src/profiler/heap-snapshot-generator.cc
+src/execution/isolate.cc
diff --git a/chromium/v8/tools/gcmole/suspects.whitelist b/chromium/v8/tools/gcmole/suspects.whitelist
index 01db7401f22..1ac855f2f76 100644
--- a/chromium/v8/tools/gcmole/suspects.whitelist
+++ b/chromium/v8/tools/gcmole/suspects.whitelist
@@ -2,3 +2,5 @@ IsConstructor
 IsEval
 IsAsync
 IsPromiseAll
+IsPromiseAny
+VisitRootPointers
diff --git a/chromium/v8/tools/gcmole/test-expectations.txt b/chromium/v8/tools/gcmole/test-expectations.txt
index 82134743f6b..780cea91811 100644
--- a/chromium/v8/tools/gcmole/test-expectations.txt
+++ b/chromium/v8/tools/gcmole/test-expectations.txt
@@ -1,4 +1,7 @@
 
+tools/gcmole/gcmole-test.cc:27:10: warning: Possibly dead variable.
+  return obj;
+         ^
 tools/gcmole/gcmole-test.cc:45:3: warning: Possible problem with evaluation order.
   TwoArgumentsFunction(*CauseGC(obj1, isolate), *CauseGC(obj2, isolate));
   ^
@@ -20,4 +23,13 @@ tools/gcmole/gcmole-test.cc:130:14: warning: Possible problem with evaluation or
 tools/gcmole/gcmole-test.cc:151:14: warning: Possible problem with evaluation order.
   so_handle->Method(*SomeClass::StaticCauseGC(obj1, isolate));
              ^
-7 warnings generated.
+tools/gcmole/gcmole-test.cc:161:3: warning: Possibly dead variable.
+  raw_obj.Print();
+  ^
+tools/gcmole/gcmole-test.cc:193:3: warning: Possibly dead variable.
+  raw_obj.Print();
+  ^
+tools/gcmole/gcmole-test.cc:216:3: warning: Possibly dead variable.
+  raw_obj.Print();
+  ^
+11 warnings generated.
diff --git a/chromium/v8/tools/gen-postmortem-metadata.py b/chromium/v8/tools/gen-postmortem-metadata.py
index b36cd20221a..84b9ad49905 100644
--- a/chromium/v8/tools/gen-postmortem-metadata.py
+++ b/chromium/v8/tools/gen-postmortem-metadata.py
@@ -223,9 +223,6 @@ consts_misc = [
         'value': 'SimpleNumberDictionaryShape::kEntrySize' },
 
     { 'name': 'type_JSError__JS_ERROR_TYPE', 'value': 'JS_ERROR_TYPE' },
-
-    { 'name': 'class_SharedFunctionInfo__function_data__Object',
-        'value': 'SharedFunctionInfo::kFunctionDataOffset' },
 ];
 
 #
@@ -263,6 +260,7 @@ extras_accessors = [
     'ExternalString, resource, Object, kResourceOffset',
     'SeqOneByteString, chars, char, kHeaderSize',
     'SeqTwoByteString, chars, char, kHeaderSize',
+    'UncompiledData, inferred_name, String, kInferredNameOffset',
     'UncompiledData, start_position, int32_t, kStartPositionOffset',
     'UncompiledData, end_position, int32_t, kEndPositionOffset',
     'SharedFunctionInfo, raw_function_token_offset, int16_t, kFunctionTokenOffsetOffset',
diff --git a/chromium/v8/tools/heap-stats/details-selection-template.html b/chromium/v8/tools/heap-stats/details-selection-template.html
index cd429bf1a5d..9f12bde4066 100644
--- a/chromium/v8/tools/heap-stats/details-selection-template.html
+++ b/chromium/v8/tools/heap-stats/details-selection-template.html
@@ -86,6 +86,17 @@ found in the LICENSE file. -->
   width: 50px;
 }
 
+.categorySelectionButtons {
+  float: right;
+}
+.categoryLabels {
+  float: left;
+  min-wdith: 200px;
+}
+.categoryContent {
+  clear: both;
+}
+
 </style>
 <section id="dataSelectionSection">
   <h2>Data selection</h2>
diff --git a/chromium/v8/tools/heap-stats/details-selection.js b/chromium/v8/tools/heap-stats/details-selection.js
index f7e32733d97..7130e19f408 100644
--- a/chromium/v8/tools/heap-stats/details-selection.js
+++ b/chromium/v8/tools/heap-stats/details-selection.js
@@ -30,6 +30,8 @@ defineCustomElement('details-selection', (templateText) =>
         .addEventListener('click', e => this.filterCurrentSelection(e));
     this.$('#category-auto-filter-btn')
         .addEventListener('click', e => this.filterTop20Categories(e));
+    this._data = undefined;
+    this.selection = undefined;
   }
 
   connectedCallback() {
@@ -38,6 +40,14 @@ defineCustomElement('details-selection', (templateText) =>
     }
   }
 
+  dataChanged() {
+    this.selection = {categories: {}};
+    this.resetUI(true);
+    this.populateIsolateSelect();
+    this.handleIsolateChange();
+    this.$('#dataSelectionSection').style.display = 'block';
+  }
+
   set data(value) {
     this._data = value;
     this.dataChanged();
@@ -85,45 +95,60 @@ defineCustomElement('details-selection', (templateText) =>
     const div = document.createElement('div');
     div.id = name;
     div.classList.add('box');
-    const ul = document.createElement('ul');
+
+    let ul = document.createElement('ul');
+    ul.className = 'categoryLabels'
+    {
+      const name_li = document.createElement('li');
+      name_li.textContent = CATEGORY_NAMES.get(name);
+      ul.appendChild(name_li);
+
+      const percent_li = document.createElement('li');
+      percent_li.textContent = '0%';
+      percent_li.id = name + 'PercentContent';
+      ul.appendChild(percent_li);
+    }
+    div.appendChild(ul);
+
+    ul = document.createElement('ul');
+    ul.className = 'categorySelectionButtons'
+    {
+      const all_li = document.createElement('li');
+      const all_button = document.createElement('button');
+      all_button.textContent = 'All';
+      all_button.addEventListener('click', e => this.selectCategory(name));
+      all_li.appendChild(all_button);
+      ul.appendChild(all_li);
+
+      const top_li = document.createElement('li');
+      const top_button = document.createElement('button');
+      top_button.textContent = 'Top 10';
+      top_button.addEventListener(
+          'click', e => this.selectCategoryTopEntries(name));
+      top_li.appendChild(top_button);
+      ul.appendChild(top_li);
+
+      const none_li = document.createElement('li');
+      const none_button = document.createElement('button');
+      none_button.textContent = 'None';
+      none_button.addEventListener('click', e => this.unselectCategory(name));
+      none_li.appendChild(none_button);
+      ul.appendChild(none_li);
+    }
     div.appendChild(ul);
-    const name_li = document.createElement('li');
-    ul.appendChild(name_li);
-    name_li.innerHTML = CATEGORY_NAMES.get(name);
-    const percent_li = document.createElement('li');
-    ul.appendChild(percent_li);
-    percent_li.innerHTML = '0%';
-    percent_li.id = name + 'PercentContent';
-    const all_li = document.createElement('li');
-    ul.appendChild(all_li);
-    const all_button = document.createElement('button');
-    all_li.appendChild(all_button);
-    all_button.innerHTML = 'All';
-    all_button.addEventListener('click', e => this.selectCategory(name));
-    const none_li = document.createElement('li');
-    ul.appendChild(none_li);
-    const none_button = document.createElement('button');
-    none_li.appendChild(none_button);
-    none_button.innerHTML = 'None';
-    none_button.addEventListener('click', e => this.unselectCategory(name));
+
     const innerDiv = document.createElement('div');
-    div.appendChild(innerDiv);
     innerDiv.id = name + 'Content';
+    innerDiv.className = 'categoryContent';
+    div.appendChild(innerDiv);
+
     const percentDiv = document.createElement('div');
-    div.appendChild(percentDiv);
     percentDiv.className = 'percentBackground';
     percentDiv.id = name + 'PercentBackground';
+    div.appendChild(percentDiv);
     return div;
   }
 
-  dataChanged() {
-    this.selection = {categories: {}};
-    this.resetUI(true);
-    this.populateIsolateSelect();
-    this.handleIsolateChange();
-    this.$('#dataSelectionSection').style.display = 'block';
-  }
-
   populateIsolateSelect() {
     let isolates = Object.entries(this.data);
     // Sorty by peak heap memory consumption.
@@ -259,7 +284,7 @@ defineCustomElement('details-selection', (templateText) =>
     });
     Object.entries(overalls).forEach(([category, category_overall]) => {
       let percents = category_overall / overall * 100;
-      this.$(`#${category}PercentContent`).innerHTML =
+      this.$(`#${category}PercentContent`).textContent =
           `${percents.toFixed(1)}%`;
       this.$('#' + category + 'PercentBackground').style.left = percents + '%';
     });
@@ -324,7 +349,7 @@ defineCustomElement('details-selection', (templateText) =>
 
   populateCategories() {
     this.clearCategories();
-    const categories = {};
+    const categories = {__proto__:null};
     for (let cat of CATEGORIES.keys()) {
       categories[cat] = [];
     }
@@ -354,6 +379,23 @@ defineCustomElement('details-selection', (templateText) =>
     this.notifySelectionChanged();
   }
 
+  selectCategoryTopEntries(category) {
+    // unselect all checkboxes in this category.
+    this.querySelectorAll('input[name=' + category + 'Checkbox]')
+        .forEach(checkbox => checkbox.checked = false);
+    const data = this.selectedData.instance_type_data;
+
+    // Get the max values for instance_types in this category
+    const categoryInstanceTypes = Array.from(CATEGORIES.get(category));
+    categoryInstanceTypes.filter(each => each in data)
+      .sort((a,b) => {
+        return data[b].overall - data[a].overall;
+      }).slice(0, 10).forEach((category) => {
+        this.$('#' + category + 'Checkbox').checked = true;
+      });
+    this.notifySelectionChanged();
+  }
+
   createCheckBox(instance_type, category) {
     const div = document.createElement('div');
     div.classList.add('instanceTypeSelectBox');
diff --git a/chromium/v8/tools/heap-stats/global-timeline.js b/chromium/v8/tools/heap-stats/global-timeline.js
index 2f16b1bdfbd..05c69f558e6 100644
--- a/chromium/v8/tools/heap-stats/global-timeline.js
+++ b/chromium/v8/tools/heap-stats/global-timeline.js
@@ -209,6 +209,10 @@ defineCustomElement('global-timeline', (templateText) =>
   }
 
   drawChart() {
+    setTimeout(() => this._drawChart(), 10);
+  }
+
+  _drawChart() {
     console.assert(this.data, 'invalid data');
     console.assert(this.selection, 'invalid selection');
 
diff --git a/chromium/v8/tools/ic-explorer.html b/chromium/v8/tools/ic-explorer.html
index 4c725163c5f..4ca552d6c97 100644
--- a/chromium/v8/tools/ic-explorer.html
+++ b/chromium/v8/tools/ic-explorer.html
@@ -339,6 +339,7 @@ code is governed by a BSD-style license that can be found in the LICENSE file.
 
     function initGroupKeySelect() {
       let select = document.getElementById("group-key");
+      select.options.length = 0;
       for (let i in properties) {
         let option = document.createElement("option");
         option.text = properties[i];
diff --git a/chromium/v8/tools/lldb_commands.py b/chromium/v8/tools/lldb_commands.py
index 2884cd60b01..dc96e5747d0 100644
--- a/chromium/v8/tools/lldb_commands.py
+++ b/chromium/v8/tools/lldb_commands.py
@@ -21,8 +21,17 @@ def current_frame(debugger):
   return current_thread(debugger).GetSelectedFrame()
 
 def no_arg_cmd(debugger, cmd):
-  current_frame(debugger).EvaluateExpression(cmd)
-  print("")
+  evaluate_result = current_frame(debugger).EvaluateExpression(cmd)
+  # When a void function is called the return value type is 0x1001 which
+  # is specified in http://tiny.cc/bigskz. This does not indicate
+  # an error so we check for that value below.
+  kNoResult = 0x1001
+  error = evaluate_result.GetError()
+  if error.fail and error.value != kNoResult:
+      print("Failed to evaluate command {} :".format(cmd))
+      print(error.description)
+  else:
+    print("")
 
 def ptr_arg_cmd(debugger, name, param, cmd):
   if not param:
@@ -41,7 +50,7 @@ def job(debugger, param, *args):
 def jlh(debugger, param, *args):
   """Print v8::Local handle value"""
   ptr_arg_cmd(debugger, 'jlh', param,
-              "_v8_internal_Print_Object(*(v8::internal::Object**)(*{}))")
+              "_v8_internal_Print_Object(*(v8::internal::Object**)({}.val_))")
 
 def jco(debugger, param, *args):
   """Print the code object at the given pc (default: current pc)"""
diff --git a/chromium/v8/tools/map-processor.html b/chromium/v8/tools/map-processor.html
index 77e0e7b19c7..b2bc3d57df4 100644
--- a/chromium/v8/tools/map-processor.html
+++ b/chromium/v8/tools/map-processor.html
@@ -369,6 +369,10 @@ dd {
   z-index: 100;
   display: none;
 }
+#searchBarInput {
+  width: 200px;
+}
+
 </style>
 <script src="./splaytree.js"></script>
 <script src="./codemap.js"></script>
@@ -503,8 +507,23 @@ define(Array.prototype, "histogram", function(mapFn) {
   return histogram;
 });
 
+
 // =========================================================================
 // EventHandlers
+function handleSearchBar(){
+  let searchBar = $('searchBarInput');
+  let searchBarInput = searchBar.value;
+  let selectedMap = V8Map.get(searchBarInput);
+  //removeAllChildren($('mapIdList'));
+  if(selectedMap){
+    let map = selectedMap;
+    document.state.map = map;
+    searchBar.className = "green";
+  } else {
+    searchBar.className = "red";
+  }
+}
+
 function handleBodyLoad() {
   let upload = $('fileReader');
   upload.onclick = (e) => $("file").click();
@@ -1253,13 +1272,23 @@ function transitionTypeToColor(type) {
     <section id="transitionView"></section>
     <br/>
 
+
+    <h2>Search Map by Address</h2>
+    <section id="searchBar"></section>
+    <input type="search" id="searchBarInput" placeholder="Search maps by address..">
+    <button onclick="handleSearchBar()">Search</button>
+    <ul id="mapIdList" title="Map Id List">
+    </ul>
+
+
     <h2>Selected Map</h2>
     <section id="mapDetails"></section>
   </div>
 
   <section>
     <h2>Instructions</h2>
-    <p>Visualize Map trees that have been gathered using <code>--trace-maps</code>.</p>
+    <p>Visualize Map trees that have been gathered using <code>path/to/d8 $FILE --trace-maps</code>.</p>
+    <p>You can inspect the transition tree in DevTools by looking at <code>document.state.timeline.values</code>.
     <h3>Keyboard Shortcuts</h3>
     <dl>
       <dt><kbd>SHIFT</kbd> + <kbd>Arrow Up</kbd></dt>
diff --git a/chromium/v8/tools/map-processor.js b/chromium/v8/tools/map-processor.js
index d743cba383a..9b261c7d1b8 100644
--- a/chromium/v8/tools/map-processor.js
+++ b/chromium/v8/tools/map-processor.js
@@ -43,17 +43,17 @@ class MapProcessor extends LogReader {
         processor: this.processFunctionMove
       },
       'map-create': {
-        parsers: [parseInt, parseInt, parseString],
+        parsers: [parseInt, parseString],
         processor: this.processMapCreate
       },
       'map': {
-        parsers: [parseString, parseInt, parseInt, parseInt, parseInt, parseInt,
+        parsers: [parseString, parseInt, parseString, parseString, parseInt, parseInt,
           parseString, parseString, parseString
         ],
         processor: this.processMap
       },
       'map-details': {
-        parsers: [parseInt, parseInt, parseString],
+        parsers: [parseInt, parseString, parseString],
         processor: this.processMapDetails
       }
     };
@@ -183,19 +183,16 @@ class MapProcessor extends LogReader {
     this.getExistingMap(id, time).deprecate();
   }
 
-  processMapCreate(time, id, string) {
+  processMapCreate(time, id) {
     // map-create events might override existing maps if the addresses get
-    // rcycled. Hence we do not check for existing maps.
+    // recycled. Hence we do not check for existing maps.
     let map = this.createMap(id, time);
-    map.description = string;
   }
 
   processMapDetails(time, id, string) {
     //TODO(cbruni): fix initial map logging.
     let map = this.getExistingMap(id, time);
-    if (!map.description) {
-      //map.description = string;
-    }
+    map.description = string;
   }
 
   createMap(id, time) {
@@ -205,8 +202,8 @@ class MapProcessor extends LogReader {
   }
 
   getExistingMap(id, time) {
-    if (id === 0) return undefined;
-    let map = V8Map.get(id);
+    if (id === "0x000000000000") return undefined;
+    let map = V8Map.get(id, time);
     if (map === undefined) {
       console.error("No map details provided: id=" + id);
       // Manually patch in a map to continue running.
@@ -334,18 +331,34 @@ class V8Map {
     return parents;
   }
 
-  static get(id) {
-    return this.cache.get(id);
+
+  static get(id, time = undefined) {
+    let maps = this.cache.get(id);
+    if(maps){
+      for (let i = 0; i < maps.length; i++) {
+        //TODO: Implement time based map search
+        if(maps[i].time === time){
+          return maps[i];
+        }
+      }
+      // default return the latest
+      return maps[maps.length-1];
+    }
   }
 
   static set(id, map) {
-    this.cache.set(id, map);
+    if(this.cache.has(id)){
+      this.cache.get(id).push(map);
+    } else {
+      this.cache.set(id, [map]);
+    }
   }
 }
 
 V8Map.cache = new Map();
 
 
+
 // ===========================================================================
 class Edge {
   constructor(type, name, reason, time, from, to) {
diff --git a/chromium/v8/tools/release/common_includes.py b/chromium/v8/tools/release/common_includes.py
index dbb3ba5f24b..fd69075872f 100644
--- a/chromium/v8/tools/release/common_includes.py
+++ b/chromium/v8/tools/release/common_includes.py
@@ -511,7 +511,7 @@ class Step(GitRecipesMixin):
   def WaitForLGTM(self):
     print ("Please wait for an LGTM, then type \"LGTM<Return>\" to commit "
            "your change. (If you need to iterate on the patch or double check "
-           "that it's sane, do so in another shell, but remember to not "
+           "that it's sensible, do so in another shell, but remember to not "
            "change the headline of the uploaded CL.")
     answer = ""
     while answer != "LGTM":
diff --git a/chromium/v8/tools/run.py b/chromium/v8/tools/run.py
index 5a656e19b59..59b3c15e682 100755
--- a/chromium/v8/tools/run.py
+++ b/chromium/v8/tools/run.py
@@ -6,7 +6,18 @@
 """This program wraps an arbitrary command since gn currently can only execute
 scripts."""
 
+from __future__ import print_function
+
 import subprocess
 import sys
 
-sys.exit(subprocess.call(sys.argv[1:]))
+result = subprocess.call(sys.argv[1:])
+if result != 0:
+  # Windows error codes such as 0xC0000005 and 0xC0000409 are much easier
+  # to recognize and differentiate in hex.
+  if result < -100:
+    # Print negative hex numbers as positive by adding 2^32.
+    print('Return code is %08X' % (result + 2**32))
+  else:
+    print('Return code is %d' % result)
+sys.exit(result)
diff --git a/chromium/v8/tools/testrunner/local/statusfile.py b/chromium/v8/tools/testrunner/local/statusfile.py
index f99941eb991..c8a1b307e41 100644
--- a/chromium/v8/tools/testrunner/local/statusfile.py
+++ b/chromium/v8/tools/testrunner/local/statusfile.py
@@ -27,12 +27,13 @@
 
 # for py2/py3 compatibility
 from __future__ import print_function
+from __future__ import absolute_import
 
 import os
 import re
 
-from variants import ALL_VARIANTS
-from utils import Freeze
+from .variants import ALL_VARIANTS
+from .utils import Freeze
 
 # Possible outcomes
 FAIL = "FAIL"
diff --git a/chromium/v8/tools/testrunner/local/statusfile_unittest.py b/chromium/v8/tools/testrunner/local/statusfile_unittest.py
index e8d5ff99cd1..3e2493c0ce6 100755
--- a/chromium/v8/tools/testrunner/local/statusfile_unittest.py
+++ b/chromium/v8/tools/testrunner/local/statusfile_unittest.py
@@ -4,10 +4,17 @@
 # found in the LICENSE file.
 
 
+from __future__ import absolute_import
+import os
+import sys
 import unittest
 
-import statusfile
-from utils import Freeze
+TOOLS_PATH = os.path.dirname(os.path.dirname(os.path.dirname(
+    os.path.abspath(__file__))))
+sys.path.append(TOOLS_PATH)
+
+from testrunner.local import statusfile
+from testrunner.local.utils import Freeze
 
 
 TEST_VARIABLES = {
diff --git a/chromium/v8/tools/testrunner/local/testsuite.py b/chromium/v8/tools/testrunner/local/testsuite.py
index 864d7346fca..a72ef4be610 100644
--- a/chromium/v8/tools/testrunner/local/testsuite.py
+++ b/chromium/v8/tools/testrunner/local/testsuite.py
@@ -223,7 +223,7 @@ class TestGenerator(object):
     return self
 
   def __next__(self):
-    return self.next()
+    return next(self)
 
   def next(self):
     return next(self._iterator)
diff --git a/chromium/v8/tools/testrunner/local/utils.py b/chromium/v8/tools/testrunner/local/utils.py
index 9128c433a04..b1c3575621c 100644
--- a/chromium/v8/tools/testrunner/local/utils.py
+++ b/chromium/v8/tools/testrunner/local/utils.py
@@ -35,7 +35,7 @@ import os
 import platform
 import re
 import subprocess
-import urllib2
+import urllib
 
 
 ### Exit codes and their meaning.
diff --git a/chromium/v8/tools/testrunner/num_fuzzer.py b/chromium/v8/tools/testrunner/num_fuzzer.py
index d4e92a61e80..7777f4c66d8 100755
--- a/chromium/v8/tools/testrunner/num_fuzzer.py
+++ b/chromium/v8/tools/testrunner/num_fuzzer.py
@@ -5,13 +5,14 @@
 # found in the LICENSE file.
 
 # for py2/py3 compatibility
+from __future__ import absolute_import
 from __future__ import print_function
 
 import random
 import sys
 
 # Adds testrunner to the path hence it has to be imported at the beggining.
-import base_runner
+from . import base_runner
 
 from testrunner.local import utils
 
diff --git a/chromium/v8/tools/testrunner/objects/testcase.py b/chromium/v8/tools/testrunner/objects/testcase.py
index 2a75cf60c45..ac4defd2d78 100644
--- a/chromium/v8/tools/testrunner/objects/testcase.py
+++ b/chromium/v8/tools/testrunner/objects/testcase.py
@@ -161,6 +161,11 @@ class TestCase(object):
             statusfile.CRASH not in self._statusfile_outcomes)
 
   @property
+  def is_fail(self):
+     return (statusfile.FAIL in self._statusfile_outcomes and
+             statusfile.PASS not in self._statusfile_outcomes)
+
+  @property
   def only_standard_variant(self):
     return statusfile.NO_VARIANTS in self._statusfile_outcomes
 
diff --git a/chromium/v8/tools/testrunner/outproc/base.py b/chromium/v8/tools/testrunner/outproc/base.py
index 9b65ca564a9..847b2242ffa 100644
--- a/chromium/v8/tools/testrunner/outproc/base.py
+++ b/chromium/v8/tools/testrunner/outproc/base.py
@@ -193,6 +193,8 @@ class ExpectedOutProc(OutProc):
             line.startswith('**') or
             line.startswith('ANDROID') or
             line.startswith('###') or
+            # Android linker warning.
+            line.startswith('WARNING: linker:') or
             # FIXME(machenbach): The test driver shouldn't try to use slow
             # asserts if they weren't compiled. This fails in optdebug=2.
             line == 'Warning: unknown flag --enable-slow-asserts.' or
diff --git a/chromium/v8/tools/testrunner/outproc/message.py b/chromium/v8/tools/testrunner/outproc/message.py
index f196cfd614b..c253b6f8e06 100644
--- a/chromium/v8/tools/testrunner/outproc/message.py
+++ b/chromium/v8/tools/testrunner/outproc/message.py
@@ -59,5 +59,7 @@ class OutProc(base.OutProc):
       not string.strip() or
       string.startswith("==") or
       string.startswith("**") or
-      string.startswith("ANDROID")
+      string.startswith("ANDROID") or
+      # Android linker warning.
+      string.startswith('WARNING: linker:')
     )
diff --git a/chromium/v8/tools/testrunner/standard_runner.py b/chromium/v8/tools/testrunner/standard_runner.py
index 10545fa5f24..9790e463437 100755
--- a/chromium/v8/tools/testrunner/standard_runner.py
+++ b/chromium/v8/tools/testrunner/standard_runner.py
@@ -5,6 +5,7 @@
 # found in the LICENSE file.
 
 # for py2/py3 compatibility
+from __future__ import absolute_import
 from __future__ import print_function
 from functools import reduce
 
@@ -15,7 +16,7 @@ import sys
 import tempfile
 
 # Adds testrunner to the path hence it has to be imported at the beggining.
-import base_runner
+from . import base_runner
 
 from testrunner.local import utils
 from testrunner.local.variants import ALL_VARIANTS
diff --git a/chromium/v8/tools/testrunner/testproc/progress.py b/chromium/v8/tools/testrunner/testproc/progress.py
index 671eebb9222..7a47c1b692a 100644
--- a/chromium/v8/tools/testrunner/testproc/progress.py
+++ b/chromium/v8/tools/testrunner/testproc/progress.py
@@ -4,6 +4,7 @@
 
 # for py2/py3 compatibility
 from __future__ import print_function
+from __future__ import absolute_import
 
 import datetime
 import json
@@ -12,7 +13,7 @@ import platform
 import subprocess
 import sys
 import time
-import util
+from . import util
 
 from . import base
 
@@ -243,15 +244,22 @@ class CompactProgressIndicator(ProgressIndicator):
       self._clear_line(self._last_status_length)
       print_failure_header(test)
       if len(stdout):
-        print(self._templates['stdout'] % stdout)
+        self.printFormatted('stdout', stdout)
       if len(stderr):
-        print(self._templates['stderr'] % stderr)
-      print("Command: %s" % result.cmd.to_string(relative=True))
+        self.printFormatted('stderr', stderr)
+      self.printFormatted(
+          'command', "Command: %s" % result.cmd.to_string(relative=True))
       if output.HasCrashed():
-        print("exit code: %s" % output.exit_code_string)
-        print("--- CRASHED ---")
-      if output.HasTimedOut():
-        print("--- TIMEOUT ---")
+        self.printFormatted(
+            'failure', "exit code: %s" % output.exit_code_string)
+        self.printFormatted('failure', "--- CRASHED ---")
+      elif output.HasTimedOut():
+        self.printFormatted('failure', "--- TIMEOUT ---")
+      else:
+        if test.is_fail:
+          self.printFormatted('failure', "--- UNEXPECTED PASS ---")
+        else:
+          self.printFormatted('failure', "--- FAILED ---")
 
   def finished(self):
     self._print_progress('Done')
@@ -272,12 +280,12 @@ class CompactProgressIndicator(ProgressIndicator):
       'mins': int(elapsed) // 60,
       'secs': int(elapsed) % 60
     }
-    status = self._truncate(status, 78)
+    status = self._truncateStatusLine(status, 78)
     self._last_status_length = len(status)
     print(status, end='')
     sys.stdout.flush()
 
-  def _truncate(self, string, length):
+  def _truncateStatusLine(self, string, length):
     if length and len(string) > (length - 3):
       return string[:(length - 3)] + "..."
     else:
@@ -296,22 +304,33 @@ class ColorProgressIndicator(CompactProgressIndicator):
                       "\033[31m-%(failed) 4d\033[0m]: %(test)s"),
       'stdout': "\033[1m%s\033[0m",
       'stderr': "\033[31m%s\033[0m",
+      'failure': "\033[1;31m%s\033[0m",
+      'command': "\033[33m%s\033[0m",
     }
     super(ColorProgressIndicator, self).__init__(templates)
 
+  def printFormatted(self, format, string):
+    print(self._templates[format] % string)
+
+  def _truncateStatusLine(self, string, length):
+    # Add some slack for the color control chars
+    return super(ColorProgressIndicator, self)._truncateStatusLine(
+        string, length + 3*9)
+
   def _clear_line(self, last_length):
     print("\033[1K\r", end='')
 
 
 class MonochromeProgressIndicator(CompactProgressIndicator):
   def __init__(self):
-    templates = {
-      'status_line': ("[%(mins)02i:%(secs)02i|%%%(progress) 4d|"
-                      "+%(passed) 4d|-%(failed) 4d]: %(test)s"),
-      'stdout': '%s',
-      'stderr': '%s',
-    }
-    super(MonochromeProgressIndicator, self).__init__(templates)
+   templates = {
+     'status_line': ("[%(mins)02i:%(secs)02i|%%%(progress) 4d|"
+                     "+%(passed) 4d|-%(failed) 4d]: %(test)s"),
+   }
+   super(MonochromeProgressIndicator, self).__init__(templates)
+
+  def printFormatted(self, format, string):
+    print(string)
 
   def _clear_line(self, last_length):
     print(("\r" + (" " * last_length) + "\r"), end='')
diff --git a/chromium/v8/tools/testrunner/testproc/timeout.py b/chromium/v8/tools/testrunner/testproc/timeout.py
index 9a4e88c8f05..026ba02cd97 100644
--- a/chromium/v8/tools/testrunner/testproc/timeout.py
+++ b/chromium/v8/tools/testrunner/testproc/timeout.py
@@ -1,3 +1,4 @@
+from __future__ import print_function
 # Copyright 2018 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
diff --git a/chromium/v8/tools/testrunner/testproc/util_unittest.py b/chromium/v8/tools/testrunner/testproc/util_unittest.py
index 243bf9789a7..5bf6a6e79ad 100644
--- a/chromium/v8/tools/testrunner/testproc/util_unittest.py
+++ b/chromium/v8/tools/testrunner/testproc/util_unittest.py
@@ -3,9 +3,18 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-from util import FixedSizeTopList
+from __future__ import absolute_import
+
+import os
+import sys
 import unittest
 
+TOOLS_PATH = os.path.dirname(os.path.dirname(os.path.dirname(
+    os.path.abspath(__file__))))
+sys.path.append(TOOLS_PATH)
+
+from testrunner.testproc.util import FixedSizeTopList
+
 class TestOrderedFixedSizeList(unittest.TestCase):
   def test_empty(self):
     ofsl = FixedSizeTopList(3)
diff --git a/chromium/v8/tools/turbolizer/README.md b/chromium/v8/tools/turbolizer/README.md
index c5ee729d64d..fa804f65e94 100644
--- a/chromium/v8/tools/turbolizer/README.md
+++ b/chromium/v8/tools/turbolizer/README.md
@@ -74,7 +74,6 @@ well as '--cpu' to specify which CPU to sample.
 Turbolizer build process
 ------------------------
 
-Turbolizer is currently migrating to TypeScript. The typescript sources reside in
-tools/turbolizer/src, and the typescript compiler will put the JavaScript output
-into tools/turbolizer/build/. The index.html file is set up to load the JavaScript
-from that directory.
+The typescript sources reside in tools/turbolizer/src, and the typescript
+compiler will put the JavaScript output into tools/turbolizer/build/. The
+index.html file is set up to load the JavaScript from that directory.
diff --git a/chromium/v8/tools/turbolizer/down-arrow.png b/chromium/v8/tools/turbolizer/down-arrow.png
new file mode 100644
index 00000000000..39339f289a3
--- /dev/null
+++ b/chromium/v8/tools/turbolizer/down-arrow.png
diff --git a/chromium/v8/tools/turbolizer/index.html b/chromium/v8/tools/turbolizer/index.html
index 268e51e0200..ea1b0b74d27 100644
--- a/chromium/v8/tools/turbolizer/index.html
+++ b/chromium/v8/tools/turbolizer/index.html
@@ -8,6 +8,7 @@ code is governed by a BSD-style license that can be found in the LICENSE file.
   <meta charset="utf-8">
   <title>V8 Turbolizer</title>
   <link rel="stylesheet" href="turbo-visualizer.css">
+  <link rel="stylesheet" href="turbo-visualizer-ranges.css">
   <link rel="stylesheet" href="tabs.css">
   <link rel="icon" type="image/png" href="turbolizer.png">
 </head>
@@ -21,6 +22,12 @@ code is governed by a BSD-style license that can be found in the LICENSE file.
       <input id="upload-helper" type="file">
       <input id="upload" type="image" title="load graph" class="button-input" src="upload-icon.png" alt="upload graph">
     </div>
+    <div id="resizer-ranges" class="resizer" style="visibility:hidden;"></div>
+    <div id="ranges" class="content" style="visibility:hidden;"></div>
+    <div id="show-hide-ranges" class="show-hide-pane" style="visibility: hidden">
+      <input id="ranges-expand" type="image" title="show ranges" src="up-arrow.png" class="button-input invisible">
+      <input id="ranges-shrink" type="image" title="hide ranges" src="down-arrow.png" class="button-input">
+    </div>
   </div>
   <div id="resizer-right" class="resizer"></div>
   <div id="right" class="content"></div>
diff --git a/chromium/v8/tools/turbolizer/src/constants.ts b/chromium/v8/tools/turbolizer/src/constants.ts
index ada39ae6b3b..47dee8547ff 100644
--- a/chromium/v8/tools/turbolizer/src/constants.ts
+++ b/chromium/v8/tools/turbolizer/src/constants.ts
@@ -14,6 +14,9 @@ export const GENERATED_PANE_ID = 'right';
 export const DISASSEMBLY_PANE_ID = 'disassembly';
 export const DISASSEMBLY_COLLAPSE_ID = 'disassembly-shrink';
 export const DISASSEMBLY_EXPAND_ID = 'disassembly-expand';
+export const RANGES_PANE_ID = "ranges";
+export const RANGES_COLLAPSE_ID = "ranges-shrink";
+export const RANGES_EXPAND_ID = "ranges-expand";
 export const UNICODE_BLOCK = '&#9611;';
 export const PROF_COLS = [
   { perc: 0, col: { r: 255, g: 255, b: 255 } },
diff --git a/chromium/v8/tools/turbolizer/src/graphmultiview.ts b/chromium/v8/tools/turbolizer/src/graphmultiview.ts
index 380f7df77db..4f8f6339199 100644
--- a/chromium/v8/tools/turbolizer/src/graphmultiview.ts
+++ b/chromium/v8/tools/turbolizer/src/graphmultiview.ts
@@ -38,6 +38,11 @@ export class GraphMultiView extends View {
     return pane;
   }
 
+  hide() {
+    this.hideCurrentPhase();
+    super.hide();
+  }
+
   constructor(id, selectionBroker, sourceResolver) {
     super(id);
     const view = this;
@@ -86,7 +91,9 @@ export class GraphMultiView extends View {
   }
 
   show() {
-    super.show();
+    // Insert before is used so that the display is inserted before the
+    // resizer for the RangeView.
+    this.container.insertBefore(this.divNode, this.container.firstChild);
     this.initializeSelect();
     const lastPhaseIndex = +window.sessionStorage.getItem("lastSelectedPhase");
     const initialPhaseIndex = this.sourceResolver.repairPhaseId(lastPhaseIndex);
diff --git a/chromium/v8/tools/turbolizer/src/range-view.ts b/chromium/v8/tools/turbolizer/src/range-view.ts
new file mode 100644
index 00000000000..17058e4f3b2
--- /dev/null
+++ b/chromium/v8/tools/turbolizer/src/range-view.ts
@@ -0,0 +1,938 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import { createElement } from "../src/util";
+import { SequenceView } from "../src/sequence-view";
+import { RegisterAllocation, Range, ChildRange, Interval } from "../src/source-resolver";
+
+class Constants {
+  // Determines how many rows each div group holds for the purposes of
+  // hiding by syncHidden.
+  static readonly ROW_GROUP_SIZE = 20;
+  static readonly POSITIONS_PER_INSTRUCTION = 4;
+  static readonly FIXED_REGISTER_LABEL_WIDTH = 6;
+
+  static readonly INTERVAL_TEXT_FOR_NONE = "none";
+  static readonly INTERVAL_TEXT_FOR_CONST = "const";
+  static readonly INTERVAL_TEXT_FOR_STACK = "stack:";
+}
+
+// This class holds references to the HTMLElements that represent each cell.
+class Grid {
+  elements: Array<Array<HTMLElement>>;
+
+  constructor() {
+    this.elements = [];
+  }
+
+  setRow(row: number, elementsRow: Array<HTMLElement>) {
+    this.elements[row] = elementsRow;
+  }
+
+  getCell(row: number, column: number) {
+    return this.elements[row][column];
+  }
+
+  getInterval(row: number, column: number) {
+    // The cell is within an inner wrapper div which is within the interval div.
+    return this.getCell(row, column).parentElement.parentElement;
+  }
+}
+
+// This class is used as a wrapper to hide the switch between the
+// two different Grid objects used, one for each phase,
+// before and after register allocation.
+class GridAccessor {
+  sequenceView: SequenceView;
+  grids: Map<number, Grid>;
+
+  constructor(sequenceView: SequenceView) {
+    this.sequenceView = sequenceView;
+    this.grids = new Map<number, Grid>();
+  }
+
+  private currentGrid() {
+    return this.grids.get(this.sequenceView.currentPhaseIndex);
+  }
+
+  getAnyGrid() {
+    return this.grids.values().next().value;
+  }
+
+  hasGrid() {
+    return this.grids.has(this.sequenceView.currentPhaseIndex);
+  }
+
+  addGrid(grid: Grid) {
+    if (this.hasGrid()) console.warn("Overwriting existing Grid.");
+    this.grids.set(this.sequenceView.currentPhaseIndex, grid);
+  }
+
+  getCell(row: number, column: number) {
+    return this.currentGrid().getCell(row, column);
+  }
+
+  getInterval(row: number, column: number) {
+    return this.currentGrid().getInterval(row, column);
+  }
+}
+
+// This class is used as a wrapper to access the interval HTMLElements
+class IntervalElementsAccessor {
+  sequenceView: SequenceView;
+  map: Map<number, Array<HTMLElement>>;
+
+  constructor(sequenceView: SequenceView) {
+    this.sequenceView = sequenceView;
+    this.map = new Map<number, Array<HTMLElement>>();
+  }
+
+  private currentIntervals() {
+    const intervals = this.map.get(this.sequenceView.currentPhaseIndex);
+    if (intervals == undefined) {
+      this.map.set(this.sequenceView.currentPhaseIndex, new Array<HTMLElement>());
+      return this.currentIntervals();
+    }
+    return intervals;
+  }
+
+  addInterval(interval: HTMLElement) {
+    this.currentIntervals().push(interval);
+  }
+
+  forEachInterval(callback: (phase: number, interval: HTMLElement) => void) {
+    for (const phase of this.map.keys()) {
+      for (const interval of this.map.get(phase)) {
+        callback(phase, interval);
+      }
+    }
+  }
+}
+
+// A simple class used to hold two Range objects. This is used to allow the two fixed register live
+// ranges of normal and deferred to be easily combined into a single row.
+class RangePair {
+  ranges: [Range, Range];
+
+  constructor(ranges: [Range, Range]) {
+    this.ranges = ranges;
+  }
+
+  forEachRange(callback: (range: Range) => void) {
+    this.ranges.forEach((range: Range) => { if (range) callback(range); });
+  }
+}
+
+// A number of css variables regarding dimensions of HTMLElements are required by RangeView.
+class CSSVariables {
+  positionWidth: number;
+  blockBorderWidth: number;
+
+  constructor() {
+    const getNumberValue = varName => {
+      return parseFloat(getComputedStyle(document.body)
+             .getPropertyValue(varName).match(/[+-]?\d+(\.\d+)?/g)[0]);
+    };
+    this.positionWidth = getNumberValue("--range-position-width");
+    this.blockBorderWidth = getNumberValue("--range-block-border");
+  }
+}
+
+// Store the required data from the blocks JSON.
+class BlocksData {
+  blockBorders: Set<number>;
+  blockInstructionCountMap: Map<number, number>;
+
+  constructor(blocks: Array<any>) {
+    this.blockBorders = new Set<number>();
+    this.blockInstructionCountMap = new Map<number, number>();
+    for (const block of blocks) {
+      this.blockInstructionCountMap.set(block.id, block.instructions.length);
+      const maxInstructionInBlock = block.instructions[block.instructions.length - 1].id;
+      this.blockBorders.add(maxInstructionInBlock);
+    }
+  }
+
+  isInstructionBorder(position: number) {
+    return ((position + 1) % Constants.POSITIONS_PER_INSTRUCTION) == 0;
+  }
+
+  isBlockBorder(position: number) {
+    return this.isInstructionBorder(position)
+        && this.blockBorders.has(Math.floor(position / Constants.POSITIONS_PER_INSTRUCTION));
+  }
+}
+
+class Divs {
+  // Already existing.
+  container: HTMLElement;
+  resizerBar: HTMLElement;
+  snapper: HTMLElement;
+
+  // Created by constructor.
+  content: HTMLElement;
+  // showOnLoad contains all content that may change depending on the JSON.
+  showOnLoad: HTMLElement;
+  xAxisLabel: HTMLElement;
+  yAxisLabel: HTMLElement;
+  registerHeaders: HTMLElement;
+  registers: HTMLElement;
+
+  // Assigned from RangeView.
+  wholeHeader: HTMLElement;
+  positionHeaders: HTMLElement;
+  yAxis: HTMLElement;
+  grid: HTMLElement;
+
+  constructor() {
+    this.container = document.getElementById("ranges");
+    this.resizerBar = document.getElementById("resizer-ranges");
+    this.snapper = document.getElementById("show-hide-ranges");
+
+    this.content = document.createElement("div");
+    this.content.appendChild(this.elementForTitle());
+
+    this.showOnLoad = document.createElement("div");
+    this.showOnLoad.style.visibility = "hidden";
+    this.content.appendChild(this.showOnLoad);
+
+    this.xAxisLabel = createElement("div", "range-header-label-x");
+    this.xAxisLabel.innerText = "Blocks, Instructions, and Positions";
+    this.showOnLoad.appendChild(this.xAxisLabel);
+    this.yAxisLabel = createElement("div", "range-header-label-y");
+    this.yAxisLabel.innerText = "Registers";
+    this.showOnLoad.appendChild(this.yAxisLabel);
+
+    this.registerHeaders = createElement("div", "range-register-labels");
+    this.registers = createElement("div", "range-registers");
+    this.registerHeaders.appendChild(this.registers);
+  }
+
+  elementForTitle() {
+    const titleEl = createElement("div", "range-title-div");
+    const titleBar = createElement("div", "range-title");
+    titleBar.appendChild(createElement("div", "", "Live Ranges"));
+    const titleHelp = createElement("div", "range-title-help", "?");
+    titleHelp.title = "Each row represents a single TopLevelLiveRange (or two if deferred exists)."
+      + "\nEach interval belongs to a LiveRange contained within that row's TopLevelLiveRange."
+      + "\nAn interval is identified by i, the index of the LiveRange within the TopLevelLiveRange,"
+      + "\nand j, the index of the interval within the LiveRange, to give i:j.";
+    titleEl.appendChild(titleBar);
+    titleEl.appendChild(titleHelp);
+    return titleEl;
+  }
+}
+
+class Helper {
+  static virtualRegisterName(registerIndex: string) {
+    return "v" + registerIndex;
+  }
+
+  static fixedRegisterName(range: Range) {
+    return range.child_ranges[0].op.text;
+  }
+
+  static getPositionElementsFromInterval(interval: HTMLElement) {
+    return interval.children[1].children;
+  }
+
+  static forEachFixedRange(source: RegisterAllocation, row: number,
+                           callback: (registerIndex: string, row: number, registerName: string,
+                                      ranges: RangePair) => void) {
+
+    const forEachRangeInMap = (rangeMap: Map<string, Range>) => {
+      // There are two fixed live ranges for each register, one for normal, another for deferred.
+      // These are combined into a single row.
+      const fixedRegisterMap = new Map<string, {ranges: [Range, Range], registerIndex: number}>();
+      for (const [registerIndex, range] of rangeMap) {
+        const registerName = this.fixedRegisterName(range);
+        if (fixedRegisterMap.has(registerName)) {
+          const entry = fixedRegisterMap.get(registerName);
+          entry.ranges[1] = range;
+          // Only use the deferred register index if no normal index exists.
+          if (!range.is_deferred) {
+            entry.registerIndex = parseInt(registerIndex, 10);
+          }
+        } else {
+          fixedRegisterMap.set(registerName, {ranges: [range, undefined],
+                                              registerIndex: parseInt(registerIndex, 10)});
+        }
+      }
+      // Sort the registers by number.
+      const sortedMap = new Map([...fixedRegisterMap.entries()].sort(([nameA, _], [nameB, __]) => {
+        // Larger numbers create longer strings.
+        if (nameA.length > nameB.length) return 1;
+        if (nameA.length < nameB.length) return -1;
+        // Sort lexicographically if same length.
+        if (nameA > nameB) return 1;
+        if (nameA < nameB) return -1;
+        return 0;
+      }));
+      for (const [registerName, {ranges, registerIndex}] of sortedMap) {
+        callback("" + (-registerIndex - 1), row, registerName, new RangePair(ranges));
+        ++row;
+      }
+    };
+
+    forEachRangeInMap(source.fixedLiveRanges);
+    forEachRangeInMap(source.fixedDoubleLiveRanges);
+
+    return row;
+  }
+}
+
+class RowConstructor {
+  view: RangeView;
+
+  constructor(view: RangeView) {
+    this.view = view;
+  }
+
+  // Constructs the row of HTMLElements for grid while providing a callback for each position
+  // depending on whether that position is the start of an interval or not.
+  // RangePair is used to allow the two fixed register live ranges of normal and deferred to be
+  // easily combined into a single row.
+  construct(grid: Grid, row: number, registerIndex: string, ranges: RangePair,
+            getElementForEmptyPosition: (position: number) => HTMLElement,
+            callbackForInterval: (position: number, interval: HTMLElement) => void) {
+    const positionArray = new Array<HTMLElement>(this.view.numPositions);
+    // Construct all of the new intervals.
+    const intervalMap = this.elementsForIntervals(registerIndex, ranges);
+    for (let position = 0; position < this.view.numPositions; ++position) {
+      const interval = intervalMap.get(position);
+      if (interval == undefined) {
+        positionArray[position] = getElementForEmptyPosition(position);
+      } else {
+        callbackForInterval(position, interval);
+        this.view.intervalsAccessor.addInterval(interval);
+        const intervalPositionElements = Helper.getPositionElementsFromInterval(interval);
+        for (let j = 0; j < intervalPositionElements.length; ++j) {
+          // Point positionsArray to the new elements.
+          positionArray[position + j] = (intervalPositionElements[j] as HTMLElement);
+        }
+        position += intervalPositionElements.length - 1;
+      }
+    }
+    grid.setRow(row, positionArray);
+    ranges.forEachRange((range: Range) => this.setUses(grid, row, range));
+  }
+
+  // This is the main function used to build new intervals.
+  // Returns a map of LifeTimePositions to intervals.
+  private elementsForIntervals(registerIndex: string, ranges: RangePair) {
+    const intervalMap = new Map<number, HTMLElement>();
+    let tooltip = "";
+    ranges.forEachRange((range: Range) => {
+      for (const childRange of range.child_ranges) {
+        switch (childRange.type) {
+          case "none":
+            tooltip = Constants.INTERVAL_TEXT_FOR_NONE;
+            break;
+          case "spill_range":
+            tooltip = Constants.INTERVAL_TEXT_FOR_STACK + registerIndex;
+            break;
+          default:
+            if (childRange.op.type == "constant") {
+              tooltip = Constants.INTERVAL_TEXT_FOR_CONST;
+            } else {
+              if (childRange.op.text) {
+                tooltip = childRange.op.text;
+              } else {
+                tooltip = childRange.op;
+              }
+            }
+            break;
+        }
+        childRange.intervals.forEach((intervalNums, index) => {
+          const interval = new Interval(intervalNums);
+          const intervalEl = this.elementForInterval(childRange, interval, tooltip,
+                                                     index, range.is_deferred);
+          intervalMap.set(interval.start, intervalEl);
+        });
+      }
+    });
+    return intervalMap;
+  }
+
+  private elementForInterval(childRange: ChildRange, interval: Interval,
+                             tooltip: string, index: number, isDeferred: boolean): HTMLElement {
+    const intervalEl = createElement("div", "range-interval");
+    const title = childRange.id + ":" + index + " " + tooltip;
+    intervalEl.setAttribute("title", isDeferred ? "deferred: " + title : title);
+    this.setIntervalColor(intervalEl, tooltip);
+    const intervalInnerWrapper = createElement("div", "range-interval-wrapper");
+    intervalEl.style.gridColumn = (interval.start + 1) + " / " + (interval.end + 1);
+    intervalInnerWrapper.style.gridTemplateColumns = "repeat(" + (interval.end - interval.start)
+                                        + ",calc(" + this.view.cssVariables.positionWidth + "ch + "
+                                        + this.view.cssVariables.blockBorderWidth + "px)";
+    const intervalTextEl = this.elementForIntervalString(tooltip, interval.end - interval.start);
+    intervalEl.appendChild(intervalTextEl);
+    for (let i = interval.start; i < interval.end; ++i) {
+      const classes = "range-position range-interval-position range-empty"
+                    + (this.view.blocksData.isBlockBorder(i) ? " range-block-border" :
+                      this.view.blocksData.isInstructionBorder(i) ? " range-instr-border" : "");
+      const positionEl = createElement("div", classes, "_");
+      positionEl.style.gridColumn = (i - interval.start + 1) + "";
+      intervalInnerWrapper.appendChild(positionEl);
+    }
+    intervalEl.appendChild(intervalInnerWrapper);
+    return intervalEl;
+  }
+
+  private setIntervalColor(interval: HTMLElement, tooltip: string) {
+    if (tooltip.includes(Constants.INTERVAL_TEXT_FOR_NONE)) return;
+    if (tooltip.includes(Constants.INTERVAL_TEXT_FOR_STACK + "-")) {
+      interval.style.backgroundColor = "rgb(250, 158, 168)";
+    } else if (tooltip.includes(Constants.INTERVAL_TEXT_FOR_STACK)) {
+      interval.style.backgroundColor = "rgb(250, 158, 100)";
+    } else if (tooltip.includes(Constants.INTERVAL_TEXT_FOR_CONST)) {
+      interval.style.backgroundColor = "rgb(153, 158, 230)";
+    } else {
+      interval.style.backgroundColor = "rgb(153, 220, 168)";
+    }
+  }
+
+  private elementForIntervalString(tooltip: string, numCells: number) {
+    const spanEl = createElement("span", "range-interval-text");
+    this.setIntervalString(spanEl, tooltip, numCells);
+    return spanEl;
+  }
+
+  // Each interval displays a string of information about it.
+  private setIntervalString(spanEl: HTMLElement, tooltip: string, numCells: number) {
+    const spacePerCell = this.view.cssVariables.positionWidth;
+    // One character space is removed to accommodate for padding.
+    const spaceAvailable = (numCells * spacePerCell) - 0.5;
+    let str = tooltip + "";
+    const length = tooltip.length;
+    spanEl.style.width = null;
+    let paddingLeft = null;
+    // Add padding if possible
+    if (length <= spaceAvailable) {
+      paddingLeft = (length == spaceAvailable) ? "0.5ch" : "1ch";
+    } else {
+      str = "";
+    }
+    spanEl.style.paddingTop = null;
+    spanEl.style.paddingLeft = paddingLeft;
+    spanEl.innerHTML = str;
+  }
+
+  private setUses(grid: Grid, row: number, range: Range) {
+    for (const liveRange of range.child_ranges) {
+      if (liveRange.uses) {
+        for (const use of liveRange.uses) {
+          grid.getCell(row, use).classList.toggle("range-use", true);
+        }
+      }
+    }
+  }
+}
+
+class RangeViewConstructor {
+  view: RangeView;
+  gridTemplateColumns: string;
+  grid: Grid;
+
+  // Group the rows in divs to make hiding/showing divs more efficient.
+  currentGroup: HTMLElement;
+  currentPlaceholderGroup: HTMLElement;
+
+  constructor(rangeView: RangeView) {
+    this.view = rangeView;
+  }
+
+  construct() {
+    this.gridTemplateColumns = "repeat(" + this.view.numPositions
+                             + ",calc(" + this.view.cssVariables.positionWidth + "ch + "
+                             + this.view.cssVariables.blockBorderWidth + "px)";
+
+    this.grid = new Grid();
+    this.view.gridAccessor.addGrid(this.grid);
+
+    this.view.divs.wholeHeader = this.elementForHeader();
+    this.view.divs.showOnLoad.appendChild(this.view.divs.wholeHeader);
+
+    const gridContainer = document.createElement("div");
+    this.view.divs.grid = this.elementForGrid();
+    this.view.divs.yAxis = createElement("div", "range-y-axis");
+    this.view.divs.yAxis.appendChild(this.view.divs.registerHeaders);
+    this.view.divs.yAxis.onscroll = () => {
+      this.view.scrollHandler.syncScroll(ToSync.TOP, this.view.divs.yAxis, this.view.divs.grid);
+      this.view.scrollHandler.saveScroll();
+    };
+    gridContainer.appendChild(this.view.divs.yAxis);
+    gridContainer.appendChild(this.view.divs.grid);
+    this.view.divs.showOnLoad.appendChild(gridContainer);
+
+    this.resetGroups();
+    let row = 0;
+    row = this.addVirtualRanges(row);
+    this.addFixedRanges(row);
+  }
+
+  // The following three functions are for constructing the groups which the rows are contained
+  // within and which make up the grid. This is so as to allow groups of rows to easily be displayed
+  // and hidden for performance reasons. As rows are constructed, they are added to the currentGroup
+  // div. Each row in currentGroup is matched with an equivalent placeholder row in
+  // currentPlaceholderGroup that will be shown when currentGroup is hidden so as to maintain the
+  // dimensions and scroll positions of the grid.
+
+  private resetGroups () {
+    this.currentGroup = createElement("div", "range-positions-group range-hidden");
+    this.currentPlaceholderGroup = createElement("div", "range-positions-group");
+  }
+
+  private appendGroupsToGrid() {
+    this.view.divs.grid.appendChild(this.currentPlaceholderGroup);
+    this.view.divs.grid.appendChild(this.currentGroup);
+  }
+
+  private addRowToGroup(row: number, rowEl: HTMLElement) {
+    this.currentGroup.appendChild(rowEl);
+    this.currentPlaceholderGroup
+        .appendChild(createElement("div", "range-positions range-positions-placeholder", "_"));
+    if ((row + 1) % Constants.ROW_GROUP_SIZE == 0) {
+      this.appendGroupsToGrid();
+      this.resetGroups();
+    }
+  }
+
+  private addVirtualRanges(row: number) {
+    const source = this.view.sequenceView.sequence.register_allocation;
+    for (const [registerIndex, range] of source.liveRanges) {
+      const registerName = Helper.virtualRegisterName(registerIndex);
+      const registerEl = this.elementForVirtualRegister(registerName);
+      this.addRowToGroup(row, this.elementForRow(row, registerIndex,
+                                                 new RangePair([range, undefined])));
+      this.view.divs.registers.appendChild(registerEl);
+      ++row;
+    }
+    return row;
+  }
+
+  private addFixedRanges(row: number) {
+    row = Helper.forEachFixedRange(this.view.sequenceView.sequence.register_allocation, row,
+                                   (registerIndex: string, row: number,
+                                    registerName: string, ranges: RangePair) => {
+      const registerEl = this.elementForFixedRegister(registerName);
+      this.addRowToGroup(row, this.elementForRow(row, registerIndex, ranges));
+      this.view.divs.registers.appendChild(registerEl);
+    });
+    if (row % Constants.ROW_GROUP_SIZE != 0) {
+      this.appendGroupsToGrid();
+    }
+  }
+
+  // Each row of positions and intervals associated with a register is contained in a single
+  // HTMLElement. RangePair is used to allow the two fixed register live ranges of normal and
+  // deferred to be easily combined into a single row.
+  private elementForRow(row: number, registerIndex: string, ranges: RangePair) {
+    const rowEl = createElement("div", "range-positions");
+    rowEl.style.gridTemplateColumns = this.gridTemplateColumns;
+
+    const getElementForEmptyPosition = (position: number) => {
+      const blockBorder = this.view.blocksData.isBlockBorder(position);
+      const classes = "range-position range-empty "
+                    + (blockBorder ? "range-block-border" :
+                    this.view.blocksData.isInstructionBorder(position) ? "range-instr-border"
+                                                                       : "range-position-border");
+      const positionEl = createElement("div", classes, "_");
+      positionEl.style.gridColumn = (position + 1) + "";
+      rowEl.appendChild(positionEl);
+      return positionEl;
+    };
+
+    const callbackForInterval = (_, interval: HTMLElement) => {
+      rowEl.appendChild(interval);
+    };
+
+    this.view.rowConstructor.construct(this.grid, row, registerIndex, ranges,
+                                       getElementForEmptyPosition, callbackForInterval);
+    return rowEl;
+  }
+
+  private elementForVirtualRegister(registerName: string) {
+    const regEl = createElement("div", "range-reg", registerName);
+    regEl.setAttribute("title", registerName);
+    return regEl;
+  }
+
+  private elementForFixedRegister(registerName: string) {
+    let text = registerName;
+    const span = "".padEnd(Constants.FIXED_REGISTER_LABEL_WIDTH - text.length, "_");
+    text = "HW - <span class='range-transparent'>" + span + "</span>" + text;
+    const regEl = createElement("div", "range-reg");
+    regEl.innerHTML = text;
+    regEl.setAttribute("title", registerName);
+    return regEl;
+  }
+
+  // The header element contains the three headers for the LifeTimePosition axis.
+  private elementForHeader() {
+    const headerEl = createElement("div", "range-header");
+    this.view.divs.positionHeaders = createElement("div", "range-position-labels");
+
+    this.view.divs.positionHeaders.appendChild(this.elementForBlockHeader());
+    this.view.divs.positionHeaders.appendChild(this.elementForInstructionHeader());
+    this.view.divs.positionHeaders.appendChild(this.elementForPositionHeader());
+
+    headerEl.appendChild(this.view.divs.positionHeaders);
+    headerEl.onscroll = () => {
+      this.view.scrollHandler.syncScroll(ToSync.LEFT,
+                                         this.view.divs.wholeHeader, this.view.divs.grid);
+      this.view.scrollHandler.saveScroll();
+    };
+    return headerEl;
+  }
+
+  // The LifeTimePosition axis shows three headers, for positions, instructions, and blocks.
+
+  private elementForBlockHeader() {
+    const headerEl = createElement("div", "range-block-ids");
+    headerEl.style.gridTemplateColumns = this.gridTemplateColumns;
+
+    const elementForBlockIndex = (index: number, firstInstruction: number, instrCount: number) => {
+      const str = "B" + index;
+      const element =
+        createElement("div", "range-block-id range-header-element range-block-border", str);
+      element.setAttribute("title", str);
+      const firstGridCol = (firstInstruction * Constants.POSITIONS_PER_INSTRUCTION) + 1;
+      const lastGridCol = firstGridCol + (instrCount * Constants.POSITIONS_PER_INSTRUCTION);
+      element.style.gridColumn = firstGridCol + " / " + lastGridCol;
+      return element;
+    };
+
+    let blockIndex = 0;
+    for (let i = 0; i < this.view.sequenceView.numInstructions;) {
+      const instrCount = this.view.blocksData.blockInstructionCountMap.get(blockIndex);
+      headerEl.appendChild(elementForBlockIndex(blockIndex, i, instrCount));
+      ++blockIndex;
+      i += instrCount;
+    }
+    return headerEl;
+  }
+
+  private elementForInstructionHeader() {
+    const headerEl = createElement("div", "range-instruction-ids");
+    headerEl.style.gridTemplateColumns = this.gridTemplateColumns;
+
+    const elementForInstructionIndex = (index: number, isBlockBorder: boolean) => {
+      const classes = "range-instruction-id range-header-element "
+                    + (isBlockBorder ? "range-block-border" : "range-instr-border");
+      const element = createElement("div", classes, "" + index);
+      element.setAttribute("title", "" + index);
+      const firstGridCol = (index * Constants.POSITIONS_PER_INSTRUCTION) + 1;
+      element.style.gridColumn = firstGridCol + " / "
+                               + (firstGridCol + Constants.POSITIONS_PER_INSTRUCTION);
+      return element;
+    };
+
+    for (let i = 0; i < this.view.sequenceView.numInstructions; ++i) {
+      const blockBorder = this.view.blocksData.blockBorders.has(i);
+      headerEl.appendChild(elementForInstructionIndex(i, blockBorder));
+    }
+    return headerEl;
+  }
+
+  private elementForPositionHeader() {
+    const headerEl = createElement("div", "range-positions range-positions-header");
+    headerEl.style.gridTemplateColumns = this.gridTemplateColumns;
+
+    const elementForPositionIndex = (index: number, isBlockBorder: boolean) => {
+      const classes = "range-position range-header-element " +
+        (isBlockBorder ? "range-block-border"
+                       : this.view.blocksData.isInstructionBorder(index) ? "range-instr-border"
+                                                                         : "range-position-border");
+      const element = createElement("div", classes, "" + index);
+      element.setAttribute("title", "" + index);
+      return element;
+    };
+
+    for (let i = 0; i < this.view.numPositions; ++i) {
+      headerEl.appendChild(elementForPositionIndex(i, this.view.blocksData.isBlockBorder(i)));
+    }
+    return headerEl;
+  }
+
+  private elementForGrid() {
+    const gridEl = createElement("div", "range-grid");
+    gridEl.onscroll = () => {
+      this.view.scrollHandler.syncScroll(ToSync.TOP, this.view.divs.grid, this.view.divs.yAxis);
+      this.view.scrollHandler.syncScroll(ToSync.LEFT,
+                                         this.view.divs.grid, this.view.divs.wholeHeader);
+      this.view.scrollHandler.saveScroll();
+    };
+    return gridEl;
+  }
+}
+
+// Handles the work required when the phase is changed.
+// Between before and after register allocation for example.
+class PhaseChangeHandler {
+  view: RangeView;
+
+  constructor(view: RangeView) {
+    this.view = view;
+  }
+
+  // Called when the phase view is switched between before and after register allocation.
+  phaseChange() {
+    if (!this.view.gridAccessor.hasGrid()) {
+      // If this phase view has not been seen yet then the intervals need to be constructed.
+      this.addNewIntervals();
+    }
+    // Show all intervals pertaining to the current phase view.
+    this.view.intervalsAccessor.forEachInterval((phase, interval) => {
+      interval.classList.toggle("range-hidden", phase != this.view.sequenceView.currentPhaseIndex);
+    });
+  }
+
+  private addNewIntervals() {
+    // All Grids should point to the same HTMLElement for empty cells in the grid,
+    // so as to avoid duplication. The current Grid is used to retrieve these elements.
+    const currentGrid = this.view.gridAccessor.getAnyGrid();
+    const newGrid = new Grid();
+    this.view.gridAccessor.addGrid(newGrid);
+    const source = this.view.sequenceView.sequence.register_allocation;
+    let row = 0;
+    for (const [registerIndex, range] of source.liveRanges) {
+      this.addnewIntervalsInRange(currentGrid, newGrid, row, registerIndex,
+                                  new RangePair([range, undefined]));
+      ++row;
+    }
+    Helper.forEachFixedRange(this.view.sequenceView.sequence.register_allocation, row,
+                             (registerIndex, row, _, ranges) => {
+      this.addnewIntervalsInRange(currentGrid, newGrid, row, registerIndex, ranges);
+    });
+  }
+
+  private addnewIntervalsInRange(currentGrid: Grid, newGrid: Grid, row: number,
+                                 registerIndex: string, ranges: RangePair) {
+    const numReplacements = new Map<HTMLElement, number>();
+
+    const getElementForEmptyPosition = (position: number) => {
+      return currentGrid.getCell(row, position);
+    };
+
+    // Inserts new interval beside existing intervals.
+    const callbackForInterval = (position: number, interval: HTMLElement) => {
+      // Overlapping intervals are placed beside each other and the relevant ones displayed.
+      let currentInterval = currentGrid.getInterval(row, position);
+      // The number of intervals already inserted is tracked so that the inserted intervals
+      // are ordered correctly.
+      const intervalsAlreadyInserted = numReplacements.get(currentInterval);
+      numReplacements.set(currentInterval, intervalsAlreadyInserted ? intervalsAlreadyInserted + 1
+                                                                    : 1);
+      if (intervalsAlreadyInserted) {
+        for (let j = 0; j < intervalsAlreadyInserted; ++j) {
+          currentInterval = (currentInterval.nextElementSibling as HTMLElement);
+        }
+      }
+      interval.classList.add("range-hidden");
+      currentInterval.insertAdjacentElement('afterend', interval);
+    };
+
+    this.view.rowConstructor.construct(newGrid, row, registerIndex, ranges,
+                                          getElementForEmptyPosition, callbackForInterval);
+  }
+}
+
+enum ToSync { LEFT, TOP }
+
+// Handles saving and syncing the scroll positions of the grid.
+class ScrollHandler {
+  divs: Divs;
+  scrollTop: number;
+  scrollLeft: number;
+  scrollTopTimeout: NodeJS.Timeout;
+  scrollLeftTimeout: NodeJS.Timeout;
+  scrollTopFunc: (this: GlobalEventHandlers, ev: Event) => any;
+  scrollLeftFunc: (this: GlobalEventHandlers, ev: Event) => any;
+
+  constructor(divs: Divs) {
+    this.divs = divs;
+  }
+
+  // This function is used to hide the rows which are not currently in view and
+  // so reduce the performance cost of things like hit tests and scrolling.
+  syncHidden() {
+
+    const getOffset = (rowEl: HTMLElement, placeholderRowEl: HTMLElement, isHidden: boolean) => {
+      return isHidden ? placeholderRowEl.offsetTop : rowEl.offsetTop;
+    };
+
+    const toHide = new Array<[HTMLElement, HTMLElement]>();
+
+    const sampleCell = this.divs.registers.children[1] as HTMLElement;
+    const buffer = 2 * sampleCell.clientHeight;
+    const min = this.divs.grid.offsetTop + this.divs.grid.scrollTop - buffer;
+    const max = min + this.divs.grid.clientHeight + buffer;
+
+    // The rows are grouped by being contained within a group div. This is so as to allow
+    // groups of rows to easily be displayed and hidden with less of a performance cost.
+    // Each row in the mainGroup div is matched with an equivalent placeholder row in
+    // the placeholderGroup div that will be shown when mainGroup is hidden so as to maintain
+    // the dimensions and scroll positions of the grid.
+
+    const rangeGroups = this.divs.grid.children;
+    for (let i = 1; i < rangeGroups.length; i += 2) {
+      const mainGroup = rangeGroups[i] as HTMLElement;
+      const placeholderGroup = rangeGroups[i - 1] as HTMLElement;
+      const isHidden = mainGroup.classList.contains("range-hidden");
+      // The offsets are used to calculate whether the group is in view.
+      const offsetMin = getOffset(mainGroup.firstChild as HTMLElement,
+                                  placeholderGroup.firstChild as HTMLElement, isHidden);
+      const offsetMax = getOffset(mainGroup.lastChild as HTMLElement,
+                                  placeholderGroup.lastChild as HTMLElement, isHidden);
+      if (offsetMax > min && offsetMin < max) {
+        if (isHidden) {
+          // Show the rows, hide the placeholders.
+          mainGroup.classList.toggle("range-hidden", false);
+          placeholderGroup.classList.toggle("range-hidden", true);
+        }
+      } else if (!isHidden) {
+        // Only hide the rows once the new rows are shown so that scrollLeft is not lost.
+        toHide.push([mainGroup, placeholderGroup]);
+      }
+    }
+    for (const [mainGroup, placeholderGroup] of toHide) {
+      // Hide the rows, show the placeholders.
+      mainGroup.classList.toggle("range-hidden", true);
+      placeholderGroup.classList.toggle("range-hidden", false);
+    }
+  }
+
+  // This function is required to keep the axes labels in line with the grid
+  // content when scrolling.
+  syncScroll(toSync: ToSync, source: HTMLElement, target: HTMLElement) {
+    // Continually delay timeout until scrolling has stopped.
+    toSync == ToSync.TOP ? clearTimeout(this.scrollTopTimeout)
+                         : clearTimeout(this.scrollLeftTimeout);
+    if (target.onscroll) {
+      if (toSync == ToSync.TOP) this.scrollTopFunc = target.onscroll;
+      else this.scrollLeftFunc = target.onscroll;
+    }
+    // Clear onscroll to prevent the target syncing back with the source.
+    target.onscroll = null;
+
+    if (toSync == ToSync.TOP) target.scrollTop = source.scrollTop;
+    else target.scrollLeft = source.scrollLeft;
+
+    // Only show / hide the grid content once scrolling has stopped.
+    if (toSync == ToSync.TOP) {
+      this.scrollTopTimeout = setTimeout(() => {
+        target.onscroll = this.scrollTopFunc;
+        this.syncHidden();
+      }, 500);
+    } else {
+      this.scrollLeftTimeout = setTimeout(() => {
+        target.onscroll = this.scrollLeftFunc;
+        this.syncHidden();
+      }, 500);
+    }
+  }
+
+  saveScroll() {
+    this.scrollLeft = this.divs.grid.scrollLeft;
+    this.scrollTop = this.divs.grid.scrollTop;
+  }
+
+  restoreScroll() {
+    if (this.scrollLeft) {
+      this.divs.grid.scrollLeft = this.scrollLeft;
+      this.divs.grid.scrollTop = this.scrollTop;
+    }
+  }
+}
+
+// RangeView displays the live range data as passed in by SequenceView.
+// The data is displayed in a grid format, with the fixed and virtual registers
+// along one axis, and the LifeTimePositions along the other. Each LifeTimePosition
+// is part of an Instruction in SequenceView, which itself is part of an Instruction
+// Block. The live ranges are displayed as intervals, each belonging to a register,
+// and spanning across a certain range of LifeTimePositions.
+// When the phase being displayed changes between before register allocation and
+// after register allocation, only the intervals need to be changed.
+export class RangeView {
+  sequenceView: SequenceView;
+
+  initialized: boolean;
+  isShown: boolean;
+  numPositions: number;
+  cssVariables: CSSVariables;
+  divs: Divs;
+  rowConstructor: RowConstructor;
+  phaseChangeHandler: PhaseChangeHandler;
+  scrollHandler: ScrollHandler;
+  blocksData: BlocksData;
+  intervalsAccessor: IntervalElementsAccessor;
+  gridAccessor: GridAccessor;
+
+  constructor(sequence: SequenceView) {
+    this.initialized = false;
+    this.isShown = false;
+    this.sequenceView = sequence;
+  }
+
+  initializeContent(blocks: Array<any>) {
+    if (!this.initialized) {
+      this.gridAccessor = new GridAccessor(this.sequenceView);
+      this.intervalsAccessor = new IntervalElementsAccessor(this.sequenceView);
+      this.cssVariables = new CSSVariables();
+      this.blocksData = new BlocksData(blocks);
+      this.divs = new Divs();
+      this.scrollHandler = new ScrollHandler(this.divs);
+      this.numPositions = this.sequenceView.numInstructions * Constants.POSITIONS_PER_INSTRUCTION;
+      this.rowConstructor = new RowConstructor(this);
+      const constructor = new RangeViewConstructor(this);
+      constructor.construct();
+      this.phaseChangeHandler = new PhaseChangeHandler(this);
+      this.initialized = true;
+    } else {
+      // If the RangeView has already been initialized then the phase must have
+      // been changed.
+      this.phaseChangeHandler.phaseChange();
+    }
+  }
+
+  show() {
+    if (!this.isShown) {
+      this.isShown = true;
+      this.divs.container.appendChild(this.divs.content);
+      this.divs.resizerBar.style.visibility = "visible";
+      this.divs.container.style.visibility = "visible";
+      this.divs.snapper.style.visibility = "visible";
+      // Dispatch a resize event to ensure that the
+      // panel is shown.
+      window.dispatchEvent(new Event('resize'));
+
+      setTimeout(() => {
+        this.scrollHandler.restoreScroll();
+        this.scrollHandler.syncHidden();
+        this.divs.showOnLoad.style.visibility = "visible";
+      }, 100);
+    }
+  }
+
+  hide() {
+    if (this.initialized) {
+      this.isShown = false;
+      this.divs.container.removeChild(this.divs.content);
+      this.divs.resizerBar.style.visibility = "hidden";
+      this.divs.container.style.visibility = "hidden";
+      this.divs.snapper.style.visibility = "hidden";
+      this.divs.showOnLoad.style.visibility = "hidden";
+    } else {
+      window.document.getElementById('ranges').style.visibility = "hidden";
+    }
+    // Dispatch a resize event to ensure that the
+    // panel is hidden.
+    window.dispatchEvent(new Event('resize'));
+  }
+
+  onresize() {
+    if (this.isShown) this.scrollHandler.syncHidden();
+  }
+}
diff --git a/chromium/v8/tools/turbolizer/src/resizer.ts b/chromium/v8/tools/turbolizer/src/resizer.ts
index 4bd771f7313..ce0519398bb 100644
--- a/chromium/v8/tools/turbolizer/src/resizer.ts
+++ b/chromium/v8/tools/turbolizer/src/resizer.ts
@@ -11,6 +11,8 @@ class Snapper {
   sourceCollapse: HTMLElement;
   disassemblyExpand: HTMLElement;
   disassemblyCollapse: HTMLElement;
+  rangesExpand: HTMLElement;
+  rangesCollapse: HTMLElement;
 
   constructor(resizer: Resizer) {
     this.resizer = resizer;
@@ -18,6 +20,8 @@ class Snapper {
     this.sourceCollapse = document.getElementById(C.SOURCE_COLLAPSE_ID);
     this.disassemblyExpand = document.getElementById(C.DISASSEMBLY_EXPAND_ID);
     this.disassemblyCollapse = document.getElementById(C.DISASSEMBLY_COLLAPSE_ID);
+    this.rangesExpand = document.getElementById(C.RANGES_EXPAND_ID);
+    this.rangesCollapse = document.getElementById(C.RANGES_COLLAPSE_ID);
 
     document.getElementById("show-hide-source").addEventListener("click", () => {
       this.resizer.resizerLeft.classed("snapped", !this.resizer.resizerLeft.classed("snapped"));
@@ -29,13 +33,20 @@ class Snapper {
       this.setDisassemblyExpanded(!this.disassemblyExpand.classList.contains("invisible"));
       this.resizer.updatePanes();
     });
+    document.getElementById("show-hide-ranges").addEventListener("click", () => {
+      this.resizer.resizerRanges.classed("snapped", !this.resizer.resizerRanges.classed("snapped"));
+      this.setRangesExpanded(!this.rangesExpand.classList.contains("invisible"));
+      this.resizer.updatePanes();
+    });
   }
 
   restoreExpandedState(): void {
     this.resizer.resizerLeft.classed("snapped", window.sessionStorage.getItem("expandedState-source") == "false");
     this.resizer.resizerRight.classed("snapped", window.sessionStorage.getItem("expandedState-disassembly") == "false");
+    this.resizer.resizerRanges.classed("snapped", window.sessionStorage.getItem("expandedState-ranges") == "false");
     this.setSourceExpanded(this.getLastExpandedState("source", true));
     this.setDisassemblyExpanded(this.getLastExpandedState("disassembly", true));
+    this.setRangesExpanded(this.getLastExpandedState("ranges", true));
   }
 
   getLastExpandedState(type: string, defaultState: boolean): boolean {
@@ -48,6 +59,7 @@ class Snapper {
     window.sessionStorage.setItem("expandedState-source", `${isSourceExpanded}`);
     this.sourceExpand.classList.toggle("invisible", isSourceExpanded);
     this.sourceCollapse.classList.toggle("invisible", !isSourceExpanded);
+    document.getElementById("show-hide-ranges").style.marginLeft = isSourceExpanded ? null : "40px";
   }
 
   setSourceExpanded(isSourceExpanded: boolean): void {
@@ -65,30 +77,53 @@ class Snapper {
     this.disassemblyUpdate(isDisassemblyExpanded);
     this.resizer.updateRightWidth();
   }
+
+  rangesUpdate(isRangesExpanded: boolean): void {
+    window.sessionStorage.setItem("expandedState-ranges", `${isRangesExpanded}`);
+    this.rangesExpand.classList.toggle("invisible", isRangesExpanded);
+    this.rangesCollapse.classList.toggle("invisible", !isRangesExpanded);
+  }
+
+  setRangesExpanded(isRangesExpanded: boolean): void {
+    this.rangesUpdate(isRangesExpanded);
+    this.resizer.updateRanges();
+  }
 }
 
 export class Resizer {
   snapper: Snapper;
   deadWidth: number;
+  deadHeight: number;
   left: HTMLElement;
   right: HTMLElement;
+  ranges: HTMLElement;
+  middle: HTMLElement;
   sepLeft: number;
   sepRight: number;
+  sepRangesHeight: number;
   panesUpdatedCallback: () => void;
   resizerRight: d3.Selection<HTMLDivElement, any, any, any>;
   resizerLeft: d3.Selection<HTMLDivElement, any, any, any>;
+  resizerRanges: d3.Selection<HTMLDivElement, any, any, any>;
 
   private readonly SOURCE_PANE_DEFAULT_PERCENT = 1 / 4;
   private readonly DISASSEMBLY_PANE_DEFAULT_PERCENT = 3 / 4;
+  private readonly RANGES_PANE_HEIGHT_DEFAULT_PERCENT = 3 / 4;
+  private readonly RESIZER_RANGES_HEIGHT_BUFFER_PERCENTAGE = 5;
+  private readonly RESIZER_SIZE = document.getElementById("resizer-ranges").offsetHeight;
 
-  constructor(panesUpdatedCallback: () => void, deadWidth: number) {
+  constructor(panesUpdatedCallback: () => void, deadWidth: number, deadHeight: number) {
     const resizer = this;
     resizer.panesUpdatedCallback = panesUpdatedCallback;
     resizer.deadWidth = deadWidth;
+    resizer.deadHeight = deadHeight;
     resizer.left = document.getElementById(C.SOURCE_PANE_ID);
     resizer.right = document.getElementById(C.GENERATED_PANE_ID);
+    resizer.ranges = document.getElementById(C.RANGES_PANE_ID);
+    resizer.middle = document.getElementById("middle");
     resizer.resizerLeft = d3.select('#resizer-left');
     resizer.resizerRight = d3.select('#resizer-right');
+    resizer.resizerRanges = d3.select('#resizer-ranges');
     // Set default sizes, if they weren't set.
     if (window.sessionStorage.getItem("source-pane-percent") === null) {
       window.sessionStorage.setItem("source-pane-percent", `${this.SOURCE_PANE_DEFAULT_PERCENT}`);
@@ -96,8 +131,11 @@ export class Resizer {
     if (window.sessionStorage.getItem("disassembly-pane-percent") === null) {
       window.sessionStorage.setItem("disassembly-pane-percent", `${this.DISASSEMBLY_PANE_DEFAULT_PERCENT}`);
     }
+    if (window.sessionStorage.getItem("ranges-pane-height-percent") === null) {
+      window.sessionStorage.setItem("ranges-pane-height-percent", `${this.RANGES_PANE_HEIGHT_DEFAULT_PERCENT}`);
+    }
 
-    this.updateWidths();
+    this.updateSizes();
 
     const dragResizeLeft = d3.drag()
       .on('drag', function () {
@@ -151,8 +189,35 @@ export class Resizer {
         resizer.resizerRight.classed("dragged", false);
       });
     resizer.resizerRight.call(dragResizeRight);
+
+    const dragResizeRanges = d3.drag()
+      .on('drag', function () {
+        const y = d3.mouse(this.parentElement)[1];
+        resizer.sepRangesHeight = Math.max(100, Math.min(y, window.innerHeight) - resizer.RESIZER_RANGES_HEIGHT_BUFFER_PERCENTAGE);
+        resizer.updatePanes();
+      })
+      .on('start', function () {
+        resizer.resizerRanges.classed("dragged", true);
+      })
+      .on('end', function () {
+        // If the panel is close enough to the bottom, treat it as if it was pulled all the way to the bottom.
+        const y = d3.mouse(this.parentElement)[1];
+        if (y >= (window.innerHeight - deadHeight)) {
+          resizer.sepRangesHeight = window.innerHeight;
+          resizer.updatePanes();
+        }
+        // Snap if dragged all the way to the bottom.
+        resizer.resizerRanges.classed("snapped", resizer.sepRangesHeight >= window.innerHeight - 1);
+        if (!resizer.isRangesSnapped()) {
+          window.sessionStorage.setItem("ranges-pane-height-percent", `${resizer.sepRangesHeight / window.innerHeight}`);
+        }
+        resizer.snapper.setRangesExpanded(!resizer.isRangesSnapped());
+        resizer.resizerRanges.classed("dragged", false);
+      });
+    resizer.resizerRanges.call(dragResizeRanges);
+
     window.onresize = function () {
-      resizer.updateWidths();
+      resizer.updateSizes();
       resizer.updatePanes();
     };
     resizer.snapper = new Snapper(resizer);
@@ -167,15 +232,70 @@ export class Resizer {
     return this.resizerRight.classed("snapped");
   }
 
+  isRangesSnapped() {
+    return this.resizerRanges.classed("snapped");
+  }
+
+  updateRangesPane() {
+    const clientHeight = window.innerHeight;
+    const rangesIsHidden = this.ranges.style.visibility == "hidden";
+    let resizerSize = this.RESIZER_SIZE;
+    if (rangesIsHidden) {
+      resizerSize = 0;
+      this.sepRangesHeight = clientHeight;
+    }
+
+    const rangeHeight = clientHeight - this.sepRangesHeight;
+    this.ranges.style.height = rangeHeight + 'px';
+    const panelWidth = this.sepRight - this.sepLeft - (2 * resizerSize);
+    this.ranges.style.width = panelWidth + 'px';
+    const multiview = document.getElementById("multiview");
+    if (multiview && multiview.style) {
+        multiview.style.height = (this.sepRangesHeight - resizerSize) + 'px';
+        multiview.style.width = panelWidth + 'px';
+    }
+
+    // Resize the range grid and labels.
+    const rangeGrid = (this.ranges.getElementsByClassName("range-grid")[0] as HTMLElement);
+    if (rangeGrid) {
+      const yAxis = (this.ranges.getElementsByClassName("range-y-axis")[0] as HTMLElement);
+      const rangeHeader = (this.ranges.getElementsByClassName("range-header")[0] as HTMLElement);
+
+      const gridWidth = panelWidth - yAxis.clientWidth;
+      rangeGrid.style.width = Math.floor(gridWidth - 1) + 'px';
+      // Take live ranges' right scrollbar into account.
+      rangeHeader.style.width = (gridWidth - rangeGrid.offsetWidth + rangeGrid.clientWidth - 1) + 'px';
+      // Set resizer to horizontal.
+      this.resizerRanges.style('width', panelWidth + 'px');
+
+      const rangeTitle = (this.ranges.getElementsByClassName("range-title-div")[0] as HTMLElement);
+      const rangeHeaderLabel = (this.ranges.getElementsByClassName("range-header-label-x")[0] as HTMLElement);
+      const gridHeight = rangeHeight - rangeHeader.clientHeight - rangeTitle.clientHeight - rangeHeaderLabel.clientHeight;
+      rangeGrid.style.height = gridHeight + 'px';
+      // Take live ranges' bottom scrollbar into account.
+      yAxis.style.height = (gridHeight - rangeGrid.offsetHeight + rangeGrid.clientHeight) + 'px';
+    }
+    this.resizerRanges.style('ranges', this.ranges.style.height);
+  }
+
   updatePanes() {
     this.left.style.width = this.sepLeft + 'px';
     this.resizerLeft.style('left', this.sepLeft + 'px');
     this.right.style.width = (document.body.getBoundingClientRect().width - this.sepRight) + 'px';
     this.resizerRight.style('right', (document.body.getBoundingClientRect().width - this.sepRight - 1) + 'px');
-
+    this.updateRangesPane();
     this.panesUpdatedCallback();
   }
 
+  updateRanges() {
+    if (this.isRangesSnapped()) {
+      this.sepRangesHeight = window.innerHeight;
+    } else {
+      const sepRangesHeight = window.sessionStorage.getItem("ranges-pane-height-percent");
+      this.sepRangesHeight = window.innerHeight * Number.parseFloat(sepRangesHeight);
+    }
+  }
+
   updateLeftWidth() {
     if (this.isLeftSnapped()) {
       this.sepLeft = 0;
@@ -194,8 +314,9 @@ export class Resizer {
     }
   }
 
-  updateWidths() {
+  updateSizes() {
     this.updateLeftWidth();
     this.updateRightWidth();
+    this.updateRanges();
   }
 }
diff --git a/chromium/v8/tools/turbolizer/src/sequence-view.ts b/chromium/v8/tools/turbolizer/src/sequence-view.ts
index 49b7e9f7b2a..187b162b1cd 100644
--- a/chromium/v8/tools/turbolizer/src/sequence-view.ts
+++ b/chromium/v8/tools/turbolizer/src/sequence-view.ts
@@ -3,12 +3,21 @@
 // found in the LICENSE file.
 
 import { Sequence } from "../src/source-resolver";
-import { isIterable } from "../src/util";
+import { createElement } from "../src/util";
 import { TextView } from "../src/text-view";
+import { RangeView } from "../src/range-view";
 
 export class SequenceView extends TextView {
   sequence: Sequence;
   searchInfo: Array<any>;
+  phaseSelect: HTMLSelectElement;
+  numInstructions: number;
+  currentPhaseIndex: number;
+  phaseIndexes: Set<number>;
+  isShown: boolean;
+  rangeView: RangeView;
+  showRangeView: boolean;
+  toggleRangeViewEl: HTMLElement;
 
   createViewElement() {
     const pane = document.createElement('div');
@@ -20,6 +29,12 @@ export class SequenceView extends TextView {
 
   constructor(parentId, broker) {
     super(parentId, broker);
+    this.numInstructions = 0;
+    this.phaseIndexes = new Set<number>();
+    this.isShown = false;
+    this.showRangeView = false;
+    this.rangeView = null;
+    this.toggleRangeViewEl = this.elementForToggleRangeView();
   }
 
   attachSelection(s) {
@@ -37,34 +52,58 @@ export class SequenceView extends TextView {
     return this.selection.detachSelection();
   }
 
+  show() {
+    this.currentPhaseIndex = this.phaseSelect.selectedIndex;
+    if (!this.isShown) {
+      this.isShown = true;
+      this.phaseIndexes.add(this.currentPhaseIndex);
+      this.container.appendChild(this.divNode);
+      this.container.getElementsByClassName("graph-toolbox")[0].appendChild(this.toggleRangeViewEl);
+    }
+    if (this.showRangeView) this.rangeView.show();
+  }
+
+  hide() {
+    // A single SequenceView object is used for two phases (i.e before and after
+    // register allocation), tracking the indexes lets the redundant hides and
+    // shows be avoided when switching between the two.
+    this.currentPhaseIndex = this.phaseSelect.selectedIndex;
+    if (!this.phaseIndexes.has(this.currentPhaseIndex)) {
+      this.isShown = false;
+      this.container.removeChild(this.divNode);
+      this.container.getElementsByClassName("graph-toolbox")[0].removeChild(this.toggleRangeViewEl);
+      if (this.showRangeView) this.rangeView.hide();
+    }
+  }
+
+  onresize() {
+    if (this.showRangeView) this.rangeView.onresize();
+  }
+
   initializeContent(data, rememberedSelection) {
     this.divNode.innerHTML = '';
     this.sequence = data.sequence;
     this.searchInfo = [];
-    this.divNode.addEventListener('click', (e: MouseEvent) => {
+    this.divNode.onclick = (e: MouseEvent) => {
       if (!(e.target instanceof HTMLElement)) return;
       const instructionId = Number.parseInt(e.target.dataset.instructionId, 10);
       if (!instructionId) return;
       if (!e.shiftKey) this.broker.broadcastClear(null);
       this.broker.broadcastInstructionSelect(null, [instructionId], true);
-    });
+    };
+    this.phaseSelect = (document.getElementById('phase-select') as HTMLSelectElement);
+    this.currentPhaseIndex = this.phaseSelect.selectedIndex;
+
     this.addBlocks(this.sequence.blocks);
+    const lastBlock = this.sequence.blocks[this.sequence.blocks.length - 1];
+    this.numInstructions = lastBlock.instructions[lastBlock.instructions.length - 1].id + 1;
+    this.addRangeView();
     this.attachSelection(rememberedSelection);
     this.show();
   }
 
   elementForBlock(block) {
     const view = this;
-    function createElement(tag: string, cls: string | Array<string>, content?: string) {
-      const el = document.createElement(tag);
-      if (isIterable(cls)) {
-        for (const c of cls) el.classList.add(c);
-      } else {
-        el.classList.add(cls);
-      }
-      if (content != undefined) el.innerHTML = content;
-      return el;
-    }
 
     function mkLinkHandler(id, handler) {
       return function (e) {
@@ -84,16 +123,33 @@ export class SequenceView extends TextView {
       return mkLinkHandler(text, view.selectionHandler);
     }
 
+    function elementForOperandWithSpan(span, text, searchInfo, isVirtual) {
+      const selectionText = isVirtual ? "virt_" + text : text;
+      span.onclick = mkOperandLinkHandler(selectionText);
+      searchInfo.push(text);
+      view.addHtmlElementForNodeId(selectionText, span);
+      const container = createElement("div", "");
+      container.appendChild(span);
+      return container;
+    }
+
     function elementForOperand(operand, searchInfo) {
-      const text = operand.text;
-      const operandEl = createElement("div", ["parameter", "tag", "clickable", operand.type], text);
+      let isVirtual = false;
+      let className = "parameter tag clickable " + operand.type;
+      if (operand.text[0] == 'v' && !(operand.tooltip && operand.tooltip.includes("Float"))) {
+        isVirtual = true;
+        className += " virtual-reg";
+      }
+      const span = createElement("span", className, operand.text);
       if (operand.tooltip) {
-        operandEl.setAttribute("title", operand.tooltip);
+        span.setAttribute("title", operand.tooltip);
       }
-      operandEl.onclick = mkOperandLinkHandler(text);
-      searchInfo.push(text);
-      view.addHtmlElementForNodeId(text, operandEl);
-      return operandEl;
+      return elementForOperandWithSpan(span, operand.text, searchInfo, isVirtual);
+    }
+
+    function elementForPhiOperand(text, searchInfo) {
+      const span = createElement("span", "parameter tag clickable virtual-reg", text);
+      return elementForOperandWithSpan(span, text, searchInfo, true);
     }
 
     function elementForInstruction(instruction, searchInfo) {
@@ -115,7 +171,7 @@ export class SequenceView extends TextView {
       const gapEl = createElement("div", "gap", "gap");
       let hasGaps = false;
       for (const gap of instruction.gaps) {
-        const moves = createElement("div", ["comma-sep-list", "gap-move"]);
+        const moves = createElement("div", "comma-sep-list gap-move");
         for (const move of gap) {
           hasGaps = true;
           const moveEl = createElement("div", "move");
@@ -137,7 +193,7 @@ export class SequenceView extends TextView {
       instContentsEl.appendChild(instEl);
 
       if (instruction.outputs.length > 0) {
-        const outputs = createElement("div", ["comma-sep-list", "input-output-list"]);
+        const outputs = createElement("div", "comma-sep-list input-output-list");
         for (const output of instruction.outputs) {
           const outputEl = elementForOperand(output, searchInfo);
           outputs.appendChild(outputEl);
@@ -147,8 +203,8 @@ export class SequenceView extends TextView {
         instEl.appendChild(assignEl);
       }
 
-      let text = instruction.opcode + instruction.flags;
-      const instLabel = createElement("div", "node-label", text)
+      const text = instruction.opcode + instruction.flags;
+      const instLabel = createElement("div", "node-label", text);
       if (instruction.opcode == "ArchNop" && instruction.outputs.length == 1 && instruction.outputs[0].tooltip) {
         instLabel.innerText = instruction.outputs[0].tooltip;
       }
@@ -158,7 +214,7 @@ export class SequenceView extends TextView {
       instEl.appendChild(instLabel);
 
       if (instruction.inputs.length > 0) {
-        const inputs = createElement("div", ["comma-sep-list", "input-output-list"]);
+        const inputs = createElement("div", "comma-sep-list input-output-list");
         for (const input of instruction.inputs) {
           const inputEl = elementForOperand(input, searchInfo);
           inputs.appendChild(inputEl);
@@ -167,7 +223,7 @@ export class SequenceView extends TextView {
       }
 
       if (instruction.temps.length > 0) {
-        const temps = createElement("div", ["comma-sep-list", "input-output-list", "temps"]);
+        const temps = createElement("div", "comma-sep-list input-output-list temps");
         for (const temp of instruction.temps) {
           const tempEl = elementForOperand(temp, searchInfo);
           temps.appendChild(tempEl);
@@ -181,12 +237,12 @@ export class SequenceView extends TextView {
     const sequenceBlock = createElement("div", "schedule-block");
     sequenceBlock.classList.toggle("deferred", block.deferred);
 
-    const blockId = createElement("div", ["block-id", "com", "clickable"], block.id);
+    const blockId = createElement("div", "block-id com clickable", block.id);
     blockId.onclick = mkBlockLinkHandler(block.id);
     sequenceBlock.appendChild(blockId);
-    const blockPred = createElement("div", ["predecessor-list", "block-list", "comma-sep-list"]);
+    const blockPred = createElement("div", "predecessor-list block-list comma-sep-list");
     for (const pred of block.predecessors) {
-      const predEl = createElement("div", ["block-id", "com", "clickable"], pred);
+      const predEl = createElement("div", "block-id com clickable", pred);
       predEl.onclick = mkBlockLinkHandler(pred);
       blockPred.appendChild(predEl);
     }
@@ -211,7 +267,7 @@ export class SequenceView extends TextView {
       phiEl.appendChild(assignEl);
 
       for (const input of phi.operands) {
-        const inputEl = createElement("div", ["parameter", "tag", "clickable"], input);
+        const inputEl = elementForPhiOperand(input, this.searchInfo);
         phiEl.appendChild(inputEl);
       }
     }
@@ -221,9 +277,9 @@ export class SequenceView extends TextView {
       instructions.appendChild(elementForInstruction(instruction, this.searchInfo));
     }
     sequenceBlock.appendChild(instructions);
-    const blockSucc = createElement("div", ["successor-list", "block-list", "comma-sep-list"]);
+    const blockSucc = createElement("div", "successor-list block-list comma-sep-list");
     for (const succ of block.successors) {
-      const succEl = createElement("div", ["block-id", "com", "clickable"], succ);
+      const succEl = createElement("div", "block-id com clickable", succ);
       succEl.onclick = mkBlockLinkHandler(succ);
       blockSucc.appendChild(succEl);
     }
@@ -239,6 +295,63 @@ export class SequenceView extends TextView {
     }
   }
 
+  addRangeView() {
+    const preventRangeView = reason => {
+      const toggleRangesInput = this.toggleRangeViewEl.firstChild as HTMLInputElement;
+      if (this.rangeView) {
+        toggleRangesInput.checked = false;
+        this.toggleRangeView(toggleRangesInput);
+      }
+      toggleRangesInput.disabled = true;
+      this.toggleRangeViewEl.style.textDecoration = "line-through";
+      this.toggleRangeViewEl.setAttribute("title", reason);
+    };
+
+    if (this.sequence.register_allocation) {
+      if (!this.rangeView) {
+        this.rangeView = new RangeView(this);
+      }
+      const source = this.sequence.register_allocation;
+      if (source.fixedLiveRanges.size == 0 && source.liveRanges.size == 0) {
+        preventRangeView("No live ranges to show");
+      } else if (this.numInstructions >= 249) {
+        // This is due to the css grid-column being limited to 1000 columns.
+        // Performance issues would otherwise impose some limit.
+        // TODO(george.wort@arm.com): Allow the user to specify an instruction range
+        //                            to display that spans less than 249 instructions.
+        preventRangeView(
+          "Live range display is only supported for sequences with less than 249 instructions");
+      }
+      if (this.showRangeView) {
+        this.rangeView.initializeContent(this.sequence.blocks);
+      }
+    } else {
+      preventRangeView("No live range data provided");
+    }
+  }
+
+  elementForToggleRangeView() {
+    const toggleRangeViewEl = createElement("label", "", "show live ranges");
+    const toggleRangesInput = createElement("input", "range-toggle-show") as HTMLInputElement;
+    toggleRangesInput.setAttribute("type", "checkbox");
+    toggleRangesInput.oninput = () => this.toggleRangeView(toggleRangesInput);
+    toggleRangeViewEl.insertBefore(toggleRangesInput, toggleRangeViewEl.firstChild);
+    return toggleRangeViewEl;
+  }
+
+  toggleRangeView(toggleRangesInput: HTMLInputElement) {
+    toggleRangesInput.disabled = true;
+    this.showRangeView = toggleRangesInput.checked;
+    if (this.showRangeView) {
+      this.rangeView.initializeContent(this.sequence.blocks);
+      this.rangeView.show();
+    } else {
+      this.rangeView.hide();
+    }
+    window.dispatchEvent(new Event('resize'));
+    toggleRangesInput.disabled = false;
+  }
+
   searchInputAction(searchBar, e) {
     e.stopPropagation();
     this.selectionHandler.clear();
diff --git a/chromium/v8/tools/turbolizer/src/source-resolver.ts b/chromium/v8/tools/turbolizer/src/source-resolver.ts
index 588eea5b995..085b44f3a75 100644
--- a/chromium/v8/tools/turbolizer/src/source-resolver.ts
+++ b/chromium/v8/tools/turbolizer/src/source-resolver.ts
@@ -83,7 +83,7 @@ interface InstructionsPhase {
   instructionOffsetToPCOffset?: any;
   blockIdtoInstructionRange?: any;
   nodeIdToInstructionRange?: any;
-  codeOffsetsInfo?: CodeOffsetsInfo
+  codeOffsetsInfo?: CodeOffsetsInfo;
 }
 
 interface GraphPhase {
@@ -100,8 +100,44 @@ export interface Schedule {
   nodes: Array<any>;
 }
 
+export class Interval {
+  start: number;
+  end: number;
+
+  constructor(numbers: [number, number]) {
+    this.start = numbers[0];
+    this.end = numbers[1];
+  }
+}
+
+export interface ChildRange {
+  id: string;
+  type: string;
+  op: any;
+  intervals: Array<[number, number]>;
+  uses: Array<number>;
+}
+
+export interface Range {
+  child_ranges: Array<ChildRange>;
+  is_deferred: boolean;
+}
+
+export class RegisterAllocation {
+  fixedDoubleLiveRanges: Map<string, Range>;
+  fixedLiveRanges: Map<string, Range>;
+  liveRanges: Map<string, Range>;
+
+  constructor(registerAllocation) {
+    this.fixedDoubleLiveRanges = new Map<string, Range>(Object.entries(registerAllocation.fixed_double_live_ranges));
+    this.fixedLiveRanges = new Map<string, Range>(Object.entries(registerAllocation.fixed_live_ranges));
+    this.liveRanges = new Map<string, Range>(Object.entries(registerAllocation.live_ranges));
+  }
+}
+
 export interface Sequence {
   blocks: Array<any>;
+  register_allocation: RegisterAllocation;
 }
 
 class CodeOffsetsInfo {
@@ -720,8 +756,11 @@ export class SourceResolver {
     phase.schedule = state;
     return phase;
   }
+
   parseSequence(phase) {
-    phase.sequence = { blocks: phase.blocks };
+    phase.sequence = { blocks: phase.blocks,
+                       register_allocation: phase.register_allocation ? new RegisterAllocation(phase.register_allocation)
+                                                                      : undefined };
     return phase;
   }
 }
diff --git a/chromium/v8/tools/turbolizer/src/turbo-visualizer.ts b/chromium/v8/tools/turbolizer/src/turbo-visualizer.ts
index 22753cdda50..2dd01c28f74 100644
--- a/chromium/v8/tools/turbolizer/src/turbo-visualizer.ts
+++ b/chromium/v8/tools/turbolizer/src/turbo-visualizer.ts
@@ -18,7 +18,7 @@ window.onload = function () {
   let sourceViews: Array<CodeView> = [];
   let selectionBroker: SelectionBroker = null;
   let sourceResolver: SourceResolver = null;
-  const resizer = new Resizer(panesUpdatedCallback, 75);
+  const resizer = new Resizer(panesUpdatedCallback, 75, 75);
   const sourceTabsContainer = document.getElementById(C.SOURCE_PANE_ID);
   const sourceTabs = new Tabs(sourceTabsContainer);
   sourceTabs.addTab("&#x2b;").classList.add("last-tab", "persistent-tab");
@@ -48,6 +48,9 @@ window.onload = function () {
       sourceViews.forEach(sv => sv.hide());
       if (multiview) multiview.hide();
       multiview = null;
+      document.getElementById("ranges").innerHTML = '';
+      document.getElementById('ranges').style.visibility = "hidden";
+      document.getElementById('show-hide-ranges').style.visibility = "hidden";
       if (disassemblyView) disassemblyView.hide();
       sourceViews = [];
       sourceResolver = new SourceResolver();
diff --git a/chromium/v8/tools/turbolizer/src/util.ts b/chromium/v8/tools/turbolizer/src/util.ts
index d9c8dcdce05..8d2fc845115 100644
--- a/chromium/v8/tools/turbolizer/src/util.ts
+++ b/chromium/v8/tools/turbolizer/src/util.ts
@@ -91,3 +91,10 @@ export function measureText(text: string) {
 export function interpolate(val: number, max: number, start: number, end: number) {
   return start + (end - start) * (val / max);
 }
+
+export function createElement(tag: string, cls: string, content?: string) {
+  const el = document.createElement(tag);
+  el.className = cls;
+  if (content != undefined) el.innerText = content;
+  return el;
+}
diff --git a/chromium/v8/tools/turbolizer/turbo-visualizer-ranges.css b/chromium/v8/tools/turbolizer/turbo-visualizer-ranges.css
new file mode 100644
index 00000000000..03976e2ec54
--- /dev/null
+++ b/chromium/v8/tools/turbolizer/turbo-visualizer-ranges.css
@@ -0,0 +1,238 @@
+/* CSS specific to the live ranges div associated with
+   the RangeView typescript class in src/range-view.ts. */
+
+:root {
+  --range-y-axis-width: 18ch;
+  --range-position-width: 3.5ch;
+  --range-block-border: 6px;
+  --range-instr-border: 3px;
+  --range-position-border: 1px;
+}
+
+.range-bold {
+  font-weight: bold;
+  color: black;
+}
+
+#ranges {
+  font-family: monospace;
+  min-height: auto;
+  overflow: hidden;
+}
+
+#resizer-ranges {
+  height: 10px;
+}
+
+.range-title-div {
+  padding: 2ch 2ch 2ch 2ch;
+  white-space: nowrap;
+  overflow: auto;
+}
+
+.range-title {
+  text-decoration: underline;
+  font-weight: bold;
+  font-size: large;
+  display: inline-block;
+}
+
+.range-title-help {
+  margin-left: 2ch;
+  width: 1ch;
+  padding: 0 0.25ch;
+  border: 1px dotted black;
+  color: slategray;
+  display: inline-block;
+}
+
+input.range-toggle-show {
+  vertical-align: middle;
+}
+
+.range-header-label-x {
+  text-align: center;
+  margin-left: 13ch;
+}
+
+.range-header-label-y {
+  width: 11ch;
+  float: left;
+  white-space: pre-wrap;
+  word-wrap: break-word;
+  margin-left: 6ch;
+  margin-top: 4ch;
+}
+
+.range-y-axis {
+  display: inline-block;
+  width: var(--range-y-axis-width);
+  overflow: hidden;
+  white-space: nowrap;
+  vertical-align: top;
+}
+
+.range-header {
+  display: flex;
+  overflow: hidden;
+  height: 8ch;
+  margin-left: var(--range-y-axis-width);
+}
+
+.range-position-labels,
+.range-register-labels {
+  background-color: lightgray;
+}
+
+.range-register-labels {
+  float: right;
+}
+
+.range-position-labels {
+  margin-top: auto;
+}
+
+.range-registers {
+  float: right;
+  overflow: hidden;
+  text-align: right;
+}
+
+.range-positions-header,
+.range-instruction-ids,
+.range-block-ids {
+  overflow: hidden;
+  white-space: nowrap;
+  display: grid;
+  grid-gap: 0;
+}
+
+.range-reg {
+  width: 13ch;
+  text-align: right;
+}
+
+.range-reg::after {
+  content: ":";
+}
+
+.range-grid {
+  overflow: auto;
+  display: inline-block;
+  white-space: nowrap;
+}
+
+.range-block-id {
+  display: inline-block;
+  text-align: center;
+}
+
+.range-instruction-id {
+  display: inline-block;
+  text-align: center;
+}
+
+.range-position {
+  display: inline-block;
+  text-align: center;
+  z-index: 1;
+}
+
+.range-transparent,
+.range-position.range-empty {
+  color: transparent;
+}
+
+.range-block-id:hover,
+.range-instruction-id:hover,
+.range-reg:hover,
+.range-position:hover {
+  background-color: rgba(0, 0, 255, 0.10);
+}
+
+.range-position.range-header-element {
+  border-bottom: 2px solid rgb(109, 107, 107);
+}
+
+.range-block-id,
+.range-instruction-id,
+.range-reg,
+.range-interval,
+.range-position {
+  position: relative;
+  border: var(--range-position-border) solid rgb(109, 107, 107);
+}
+
+.range-block-id,
+.range-instruction-id,
+.range-interval,
+.range-position {
+  border-left: 0;
+}
+
+.range-block-ids > .range-block-id:first-child,
+.range-instruction-ids > .range-instruction-id:first-child,
+.range-positions > .range-position:first-child {
+  border-left: var(--range-position-border) solid rgb(109, 107, 107);
+}
+
+.range-position.range-interval-position {
+  border: none;
+}
+
+.range-interval-text {
+  position: absolute;
+  padding-left: 0.5ch;
+  z-index: 2;
+  pointer-events: none
+}
+
+.range-position.range-use {
+  border-left: var(--range-instr-border) solid red;
+}
+
+.range-block-border,
+.range-block-border.range-position.range-interval-position:last-child {
+  border-right: var(--range-block-border) solid rgb(109, 107, 107);
+}
+
+.range-block-border.range-position.range-interval-position {
+  border-right: var(--range-block-border) solid transparent;
+}
+
+.range-instr-border,
+.range-instr-border.range-position.range-interval-position:last-child {
+  border-right: var(--range-instr-border) solid rgb(109, 107, 107);
+}
+
+.range-instr-border.range-position.range-interval-position {
+  border-right: var(--range-instr-border) solid transparent;
+}
+
+.range,
+.range-interval,
+.range-interval-wrapper,
+.range-positions {
+  white-space: nowrap;
+  display: inline-block;
+}
+
+.range-interval-wrapper,
+.range-positions {
+  display: grid;
+  grid-gap: 0;
+}
+
+.range-interval {
+  background-color: rgb(153, 158, 168);
+}
+
+.range-hidden {
+  display: none !important;
+}
+
+.range-positions-placeholder {
+  width: 100%;
+  border: var(--range-position-border) solid transparent;
+  color: transparent;
+}
\ No newline at end of file
diff --git a/chromium/v8/tools/turbolizer/turbo-visualizer.css b/chromium/v8/tools/turbolizer/turbo-visualizer.css
index 6fb6da3b794..c7da769eb5d 100644
--- a/chromium/v8/tools/turbolizer/turbo-visualizer.css
+++ b/chromium/v8/tools/turbolizer/turbo-visualizer.css
@@ -342,6 +342,13 @@ input:hover,
   background-color: #F8F8F8;
   user-select: none;
   flex: 1;
+  z-index: 7;
+}
+
+#middle.display-inline-flex,
+#middle.display-inline-flex #multiview,
+#middle.display-inline-flex #ranges {
+  display: inline-flex;
 }
 
 .viewpane {
@@ -351,11 +358,6 @@ input:hover,
   flex-direction: column;
 }
 
-.multiview {
-  width: 100%;
-}
-
-
 #show-hide-disassembly {
   right: 0;
 }
@@ -423,6 +425,10 @@ text {
   dominant-baseline: text-before-edge;
 }
 
+.tab-content {
+  z-index: 6;
+}
+
 .resizer {
   z-index: 10;
   width: 10px;
@@ -595,6 +601,10 @@ text {
   padding-right: .5ex;
 }
 
+.instruction span {
+  padding-right: 0;
+}
+
 .phi-label,
 .instruction-id {
   display: inline-block;
@@ -626,6 +636,10 @@ text {
   display: inline-block;
 }
 
+.phi span {
+  padding-right: 0;
+}
+
 .gap .gap-move {
   padding-left: .5ex;
   padding-right: .5ex;
@@ -639,6 +653,10 @@ text {
   content: ")";
 }
 
+.virtual-reg {
+  outline: 1px dotted blue;
+}
+
 .parameter.constant {
   outline: 1px dotted red;
 }
diff --git a/chromium/v8/tools/turbolizer/up-arrow.png b/chromium/v8/tools/turbolizer/up-arrow.png
new file mode 100644
index 00000000000..68cb14e80b3
--- /dev/null
+++ b/chromium/v8/tools/turbolizer/up-arrow.png
diff --git a/chromium/v8/tools/v8_presubmit.py b/chromium/v8/tools/v8_presubmit.py
index 40677b3a0a3..587f8082a5f 100755
--- a/chromium/v8/tools/v8_presubmit.py
+++ b/chromium/v8/tools/v8_presubmit.py
@@ -59,12 +59,16 @@ from testrunner.local import utils
 #   We now run our own header guard check in PRESUBMIT.py.
 # build/include_what_you_use: Started giving false positives for variables
 #   named "string" and "map" assuming that you needed to include STL headers.
+# runtime/references: As of May 2020 the C++ style guide suggests using
+#   references for out parameters, see
+#   https://google.github.io/styleguide/cppguide.html#Inputs_and_Outputs.
 
 LINT_RULES = """
 -build/header_guard
 -build/include_what_you_use
 -readability/fn_size
 -readability/multiline_comment
+-runtime/references
 -whitespace/comments
 """.split()
 
diff --git a/chromium/v8/tools/v8heapconst.py b/chromium/v8/tools/v8heapconst.py
index ac69cfb836b..57b1cf26bbd 100644
--- a/chromium/v8/tools/v8heapconst.py
+++ b/chromium/v8/tools/v8heapconst.py
@@ -72,31 +72,31 @@ INSTANCE_TYPES = {
   108: "TEMPLATE_OBJECT_DESCRIPTION_TYPE",
   109: "TUPLE2_TYPE",
   110: "WASM_CAPI_FUNCTION_DATA_TYPE",
-  111: "WASM_DEBUG_INFO_TYPE",
-  112: "WASM_EXCEPTION_TAG_TYPE",
-  113: "WASM_EXPORTED_FUNCTION_DATA_TYPE",
-  114: "WASM_INDIRECT_FUNCTION_TABLE_TYPE",
-  115: "WASM_JS_FUNCTION_DATA_TYPE",
-  116: "WASM_VALUE_TYPE",
-  117: "FIXED_ARRAY_TYPE",
-  118: "HASH_TABLE_TYPE",
-  119: "EPHEMERON_HASH_TABLE_TYPE",
-  120: "GLOBAL_DICTIONARY_TYPE",
-  121: "NAME_DICTIONARY_TYPE",
-  122: "NUMBER_DICTIONARY_TYPE",
-  123: "ORDERED_HASH_MAP_TYPE",
-  124: "ORDERED_HASH_SET_TYPE",
-  125: "ORDERED_NAME_DICTIONARY_TYPE",
-  126: "SIMPLE_NUMBER_DICTIONARY_TYPE",
-  127: "STRING_TABLE_TYPE",
-  128: "CLOSURE_FEEDBACK_CELL_ARRAY_TYPE",
-  129: "OBJECT_BOILERPLATE_DESCRIPTION_TYPE",
-  130: "SCOPE_INFO_TYPE",
-  131: "SCRIPT_CONTEXT_TABLE_TYPE",
-  132: "BYTE_ARRAY_TYPE",
-  133: "BYTECODE_ARRAY_TYPE",
-  134: "FIXED_DOUBLE_ARRAY_TYPE",
-  135: "INTERNAL_CLASS_WITH_SMI_ELEMENTS_TYPE",
+  111: "WASM_EXCEPTION_TAG_TYPE",
+  112: "WASM_EXPORTED_FUNCTION_DATA_TYPE",
+  113: "WASM_INDIRECT_FUNCTION_TABLE_TYPE",
+  114: "WASM_JS_FUNCTION_DATA_TYPE",
+  115: "WASM_VALUE_TYPE",
+  116: "FIXED_ARRAY_TYPE",
+  117: "HASH_TABLE_TYPE",
+  118: "EPHEMERON_HASH_TABLE_TYPE",
+  119: "GLOBAL_DICTIONARY_TYPE",
+  120: "NAME_DICTIONARY_TYPE",
+  121: "NUMBER_DICTIONARY_TYPE",
+  122: "ORDERED_HASH_MAP_TYPE",
+  123: "ORDERED_HASH_SET_TYPE",
+  124: "ORDERED_NAME_DICTIONARY_TYPE",
+  125: "SIMPLE_NUMBER_DICTIONARY_TYPE",
+  126: "STRING_TABLE_TYPE",
+  127: "CLOSURE_FEEDBACK_CELL_ARRAY_TYPE",
+  128: "OBJECT_BOILERPLATE_DESCRIPTION_TYPE",
+  129: "SCOPE_INFO_TYPE",
+  130: "SCRIPT_CONTEXT_TABLE_TYPE",
+  131: "BYTE_ARRAY_TYPE",
+  132: "BYTECODE_ARRAY_TYPE",
+  133: "FIXED_DOUBLE_ARRAY_TYPE",
+  134: "INTERNAL_CLASS_WITH_SMI_ELEMENTS_TYPE",
+  135: "SLOPPY_ARGUMENTS_ELEMENTS_TYPE",
   136: "AWAIT_CONTEXT_TYPE",
   137: "BLOCK_CONTEXT_TYPE",
   138: "CATCH_CONTEXT_TYPE",
@@ -107,46 +107,48 @@ INSTANCE_TYPES = {
   143: "NATIVE_CONTEXT_TYPE",
   144: "SCRIPT_CONTEXT_TYPE",
   145: "WITH_CONTEXT_TYPE",
-  146: "SMALL_ORDERED_HASH_MAP_TYPE",
-  147: "SMALL_ORDERED_HASH_SET_TYPE",
-  148: "SMALL_ORDERED_NAME_DICTIONARY_TYPE",
-  149: "EXPORTED_SUB_CLASS_BASE_TYPE",
-  150: "EXPORTED_SUB_CLASS_TYPE",
-  151: "SOURCE_TEXT_MODULE_TYPE",
-  152: "SYNTHETIC_MODULE_TYPE",
-  153: "UNCOMPILED_DATA_WITH_PREPARSE_DATA_TYPE",
-  154: "UNCOMPILED_DATA_WITHOUT_PREPARSE_DATA_TYPE",
-  155: "WEAK_FIXED_ARRAY_TYPE",
-  156: "TRANSITION_ARRAY_TYPE",
-  157: "CELL_TYPE",
-  158: "CODE_TYPE",
-  159: "CODE_DATA_CONTAINER_TYPE",
-  160: "COVERAGE_INFO_TYPE",
-  161: "DESCRIPTOR_ARRAY_TYPE",
-  162: "EMBEDDER_DATA_ARRAY_TYPE",
-  163: "FEEDBACK_METADATA_TYPE",
-  164: "FEEDBACK_VECTOR_TYPE",
-  165: "FILLER_TYPE",
-  166: "FREE_SPACE_TYPE",
-  167: "INTERNAL_CLASS_TYPE",
-  168: "INTERNAL_CLASS_WITH_STRUCT_ELEMENTS_TYPE",
-  169: "MAP_TYPE",
-  170: "PREPARSE_DATA_TYPE",
-  171: "PROPERTY_ARRAY_TYPE",
-  172: "PROPERTY_CELL_TYPE",
-  173: "SHARED_FUNCTION_INFO_TYPE",
-  174: "SMI_BOX_TYPE",
-  175: "SMI_PAIR_TYPE",
-  176: "SORT_STATE_TYPE",
-  177: "WASM_ARRAY_TYPE",
-  178: "WASM_STRUCT_TYPE",
-  179: "WEAK_ARRAY_LIST_TYPE",
-  180: "WEAK_CELL_TYPE",
-  181: "JS_PROXY_TYPE",
+  146: "EXPORTED_SUB_CLASS_BASE_TYPE",
+  147: "EXPORTED_SUB_CLASS_TYPE",
+  148: "EXPORTED_SUB_CLASS2_TYPE",
+  149: "SMALL_ORDERED_HASH_MAP_TYPE",
+  150: "SMALL_ORDERED_HASH_SET_TYPE",
+  151: "SMALL_ORDERED_NAME_DICTIONARY_TYPE",
+  152: "SOURCE_TEXT_MODULE_TYPE",
+  153: "SYNTHETIC_MODULE_TYPE",
+  154: "UNCOMPILED_DATA_WITH_PREPARSE_DATA_TYPE",
+  155: "UNCOMPILED_DATA_WITHOUT_PREPARSE_DATA_TYPE",
+  156: "WEAK_FIXED_ARRAY_TYPE",
+  157: "TRANSITION_ARRAY_TYPE",
+  158: "CELL_TYPE",
+  159: "CODE_TYPE",
+  160: "CODE_DATA_CONTAINER_TYPE",
+  161: "COVERAGE_INFO_TYPE",
+  162: "DESCRIPTOR_ARRAY_TYPE",
+  163: "EMBEDDER_DATA_ARRAY_TYPE",
+  164: "FEEDBACK_METADATA_TYPE",
+  165: "FEEDBACK_VECTOR_TYPE",
+  166: "FILLER_TYPE",
+  167: "FREE_SPACE_TYPE",
+  168: "INTERNAL_CLASS_TYPE",
+  169: "INTERNAL_CLASS_WITH_STRUCT_ELEMENTS_TYPE",
+  170: "MAP_TYPE",
+  171: "ON_HEAP_BASIC_BLOCK_PROFILER_DATA_TYPE",
+  172: "PREPARSE_DATA_TYPE",
+  173: "PROPERTY_ARRAY_TYPE",
+  174: "PROPERTY_CELL_TYPE",
+  175: "SHARED_FUNCTION_INFO_TYPE",
+  176: "SMI_BOX_TYPE",
+  177: "SMI_PAIR_TYPE",
+  178: "SORT_STATE_TYPE",
+  179: "WASM_ARRAY_TYPE",
+  180: "WASM_STRUCT_TYPE",
+  181: "WEAK_ARRAY_LIST_TYPE",
+  182: "WEAK_CELL_TYPE",
+  183: "JS_PROXY_TYPE",
   1057: "JS_OBJECT_TYPE",
-  182: "JS_GLOBAL_OBJECT_TYPE",
-  183: "JS_GLOBAL_PROXY_TYPE",
-  184: "JS_MODULE_NAMESPACE_TYPE",
+  184: "JS_GLOBAL_OBJECT_TYPE",
+  185: "JS_GLOBAL_PROXY_TYPE",
+  186: "JS_MODULE_NAMESPACE_TYPE",
   1040: "JS_SPECIAL_API_OBJECT_TYPE",
   1041: "JS_PRIMITIVE_WRAPPER_TYPE",
   1042: "JS_MAP_KEY_ITERATOR_TYPE",
@@ -164,195 +166,196 @@ INSTANCE_TYPES = {
   1054: "JS_WEAK_MAP_TYPE",
   1055: "JS_WEAK_SET_TYPE",
   1056: "JS_API_OBJECT_TYPE",
-  1058: "JS_AGGREGATE_ERROR_TYPE",
-  1059: "JS_ARGUMENTS_OBJECT_TYPE",
-  1060: "JS_ARRAY_TYPE",
-  1061: "JS_ARRAY_BUFFER_TYPE",
-  1062: "JS_ARRAY_ITERATOR_TYPE",
-  1063: "JS_ASYNC_FROM_SYNC_ITERATOR_TYPE",
-  1064: "JS_COLLATOR_TYPE",
-  1065: "JS_CONTEXT_EXTENSION_OBJECT_TYPE",
-  1066: "JS_DATE_TYPE",
-  1067: "JS_DATE_TIME_FORMAT_TYPE",
-  1068: "JS_DISPLAY_NAMES_TYPE",
-  1069: "JS_ERROR_TYPE",
-  1070: "JS_FINALIZATION_REGISTRY_TYPE",
-  1071: "JS_LIST_FORMAT_TYPE",
-  1072: "JS_LOCALE_TYPE",
-  1073: "JS_MESSAGE_OBJECT_TYPE",
-  1074: "JS_NUMBER_FORMAT_TYPE",
-  1075: "JS_PLURAL_RULES_TYPE",
-  1076: "JS_PROMISE_TYPE",
-  1077: "JS_REG_EXP_TYPE",
-  1078: "JS_REG_EXP_STRING_ITERATOR_TYPE",
-  1079: "JS_RELATIVE_TIME_FORMAT_TYPE",
-  1080: "JS_SEGMENT_ITERATOR_TYPE",
-  1081: "JS_SEGMENTER_TYPE",
-  1082: "JS_STRING_ITERATOR_TYPE",
-  1083: "JS_V8_BREAK_ITERATOR_TYPE",
-  1084: "JS_WEAK_REF_TYPE",
-  1085: "WASM_EXCEPTION_OBJECT_TYPE",
-  1086: "WASM_GLOBAL_OBJECT_TYPE",
-  1087: "WASM_INSTANCE_OBJECT_TYPE",
-  1088: "WASM_MEMORY_OBJECT_TYPE",
-  1089: "WASM_MODULE_OBJECT_TYPE",
-  1090: "WASM_TABLE_OBJECT_TYPE",
-  1091: "JS_BOUND_FUNCTION_TYPE",
-  1092: "JS_FUNCTION_TYPE",
+  1058: "JS_ARGUMENTS_OBJECT_TYPE",
+  1059: "JS_ARRAY_TYPE",
+  1060: "JS_ARRAY_BUFFER_TYPE",
+  1061: "JS_ARRAY_ITERATOR_TYPE",
+  1062: "JS_ASYNC_FROM_SYNC_ITERATOR_TYPE",
+  1063: "JS_COLLATOR_TYPE",
+  1064: "JS_CONTEXT_EXTENSION_OBJECT_TYPE",
+  1065: "JS_DATE_TYPE",
+  1066: "JS_DATE_TIME_FORMAT_TYPE",
+  1067: "JS_DISPLAY_NAMES_TYPE",
+  1068: "JS_ERROR_TYPE",
+  1069: "JS_FINALIZATION_REGISTRY_TYPE",
+  1070: "JS_LIST_FORMAT_TYPE",
+  1071: "JS_LOCALE_TYPE",
+  1072: "JS_MESSAGE_OBJECT_TYPE",
+  1073: "JS_NUMBER_FORMAT_TYPE",
+  1074: "JS_PLURAL_RULES_TYPE",
+  1075: "JS_PROMISE_TYPE",
+  1076: "JS_REG_EXP_TYPE",
+  1077: "JS_REG_EXP_STRING_ITERATOR_TYPE",
+  1078: "JS_RELATIVE_TIME_FORMAT_TYPE",
+  1079: "JS_SEGMENT_ITERATOR_TYPE",
+  1080: "JS_SEGMENTER_TYPE",
+  1081: "JS_STRING_ITERATOR_TYPE",
+  1082: "JS_V8_BREAK_ITERATOR_TYPE",
+  1083: "JS_WEAK_REF_TYPE",
+  1084: "WASM_EXCEPTION_OBJECT_TYPE",
+  1085: "WASM_GLOBAL_OBJECT_TYPE",
+  1086: "WASM_INSTANCE_OBJECT_TYPE",
+  1087: "WASM_MEMORY_OBJECT_TYPE",
+  1088: "WASM_MODULE_OBJECT_TYPE",
+  1089: "WASM_TABLE_OBJECT_TYPE",
+  1090: "JS_BOUND_FUNCTION_TYPE",
+  1091: "JS_FUNCTION_TYPE",
 }
 
 # List of known V8 maps.
 KNOWN_MAPS = {
-  ("read_only_space", 0x00121): (166, "FreeSpaceMap"),
-  ("read_only_space", 0x00149): (169, "MetaMap"),
+  ("read_only_space", 0x00121): (167, "FreeSpaceMap"),
+  ("read_only_space", 0x00149): (170, "MetaMap"),
   ("read_only_space", 0x0018d): (67, "NullMap"),
-  ("read_only_space", 0x001c5): (161, "DescriptorArrayMap"),
-  ("read_only_space", 0x001f5): (155, "WeakFixedArrayMap"),
-  ("read_only_space", 0x0021d): (165, "OnePointerFillerMap"),
-  ("read_only_space", 0x00245): (165, "TwoPointerFillerMap"),
+  ("read_only_space", 0x001c5): (162, "DescriptorArrayMap"),
+  ("read_only_space", 0x001f5): (156, "WeakFixedArrayMap"),
+  ("read_only_space", 0x0021d): (166, "OnePointerFillerMap"),
+  ("read_only_space", 0x00245): (166, "TwoPointerFillerMap"),
   ("read_only_space", 0x00289): (67, "UninitializedMap"),
   ("read_only_space", 0x002cd): (8, "OneByteInternalizedStringMap"),
   ("read_only_space", 0x00329): (67, "UndefinedMap"),
   ("read_only_space", 0x0035d): (66, "HeapNumberMap"),
   ("read_only_space", 0x003a1): (67, "TheHoleMap"),
   ("read_only_space", 0x00401): (67, "BooleanMap"),
-  ("read_only_space", 0x00489): (132, "ByteArrayMap"),
-  ("read_only_space", 0x004b1): (117, "FixedArrayMap"),
-  ("read_only_space", 0x004d9): (117, "FixedCOWArrayMap"),
-  ("read_only_space", 0x00501): (118, "HashTableMap"),
+  ("read_only_space", 0x00489): (131, "ByteArrayMap"),
+  ("read_only_space", 0x004b1): (116, "FixedArrayMap"),
+  ("read_only_space", 0x004d9): (116, "FixedCOWArrayMap"),
+  ("read_only_space", 0x00501): (117, "HashTableMap"),
   ("read_only_space", 0x00529): (64, "SymbolMap"),
   ("read_only_space", 0x00551): (40, "OneByteStringMap"),
-  ("read_only_space", 0x00579): (130, "ScopeInfoMap"),
-  ("read_only_space", 0x005a1): (173, "SharedFunctionInfoMap"),
-  ("read_only_space", 0x005c9): (158, "CodeMap"),
-  ("read_only_space", 0x005f1): (157, "CellMap"),
-  ("read_only_space", 0x00619): (172, "GlobalPropertyCellMap"),
+  ("read_only_space", 0x00579): (129, "ScopeInfoMap"),
+  ("read_only_space", 0x005a1): (175, "SharedFunctionInfoMap"),
+  ("read_only_space", 0x005c9): (159, "CodeMap"),
+  ("read_only_space", 0x005f1): (158, "CellMap"),
+  ("read_only_space", 0x00619): (174, "GlobalPropertyCellMap"),
   ("read_only_space", 0x00641): (70, "ForeignMap"),
-  ("read_only_space", 0x00669): (156, "TransitionArrayMap"),
+  ("read_only_space", 0x00669): (157, "TransitionArrayMap"),
   ("read_only_space", 0x00691): (45, "ThinOneByteStringMap"),
-  ("read_only_space", 0x006b9): (164, "FeedbackVectorMap"),
+  ("read_only_space", 0x006b9): (165, "FeedbackVectorMap"),
   ("read_only_space", 0x0070d): (67, "ArgumentsMarkerMap"),
   ("read_only_space", 0x0076d): (67, "ExceptionMap"),
   ("read_only_space", 0x007c9): (67, "TerminationExceptionMap"),
   ("read_only_space", 0x00831): (67, "OptimizedOutMap"),
   ("read_only_space", 0x00891): (67, "StaleRegisterMap"),
-  ("read_only_space", 0x008d5): (131, "ScriptContextTableMap"),
-  ("read_only_space", 0x008fd): (128, "ClosureFeedbackCellArrayMap"),
-  ("read_only_space", 0x00925): (163, "FeedbackMetadataArrayMap"),
-  ("read_only_space", 0x0094d): (117, "ArrayListMap"),
+  ("read_only_space", 0x008d5): (130, "ScriptContextTableMap"),
+  ("read_only_space", 0x008fd): (127, "ClosureFeedbackCellArrayMap"),
+  ("read_only_space", 0x00925): (164, "FeedbackMetadataArrayMap"),
+  ("read_only_space", 0x0094d): (116, "ArrayListMap"),
   ("read_only_space", 0x00975): (65, "BigIntMap"),
-  ("read_only_space", 0x0099d): (129, "ObjectBoilerplateDescriptionMap"),
-  ("read_only_space", 0x009c5): (133, "BytecodeArrayMap"),
-  ("read_only_space", 0x009ed): (159, "CodeDataContainerMap"),
-  ("read_only_space", 0x00a15): (160, "CoverageInfoMap"),
-  ("read_only_space", 0x00a3d): (134, "FixedDoubleArrayMap"),
-  ("read_only_space", 0x00a65): (120, "GlobalDictionaryMap"),
+  ("read_only_space", 0x0099d): (128, "ObjectBoilerplateDescriptionMap"),
+  ("read_only_space", 0x009c5): (132, "BytecodeArrayMap"),
+  ("read_only_space", 0x009ed): (160, "CodeDataContainerMap"),
+  ("read_only_space", 0x00a15): (161, "CoverageInfoMap"),
+  ("read_only_space", 0x00a3d): (133, "FixedDoubleArrayMap"),
+  ("read_only_space", 0x00a65): (119, "GlobalDictionaryMap"),
   ("read_only_space", 0x00a8d): (96, "ManyClosuresCellMap"),
-  ("read_only_space", 0x00ab5): (117, "ModuleInfoMap"),
-  ("read_only_space", 0x00add): (121, "NameDictionaryMap"),
+  ("read_only_space", 0x00ab5): (116, "ModuleInfoMap"),
+  ("read_only_space", 0x00add): (120, "NameDictionaryMap"),
   ("read_only_space", 0x00b05): (96, "NoClosuresCellMap"),
-  ("read_only_space", 0x00b2d): (122, "NumberDictionaryMap"),
+  ("read_only_space", 0x00b2d): (121, "NumberDictionaryMap"),
   ("read_only_space", 0x00b55): (96, "OneClosureCellMap"),
-  ("read_only_space", 0x00b7d): (123, "OrderedHashMapMap"),
-  ("read_only_space", 0x00ba5): (124, "OrderedHashSetMap"),
-  ("read_only_space", 0x00bcd): (125, "OrderedNameDictionaryMap"),
-  ("read_only_space", 0x00bf5): (170, "PreparseDataMap"),
-  ("read_only_space", 0x00c1d): (171, "PropertyArrayMap"),
+  ("read_only_space", 0x00b7d): (122, "OrderedHashMapMap"),
+  ("read_only_space", 0x00ba5): (123, "OrderedHashSetMap"),
+  ("read_only_space", 0x00bcd): (124, "OrderedNameDictionaryMap"),
+  ("read_only_space", 0x00bf5): (172, "PreparseDataMap"),
+  ("read_only_space", 0x00c1d): (173, "PropertyArrayMap"),
   ("read_only_space", 0x00c45): (92, "SideEffectCallHandlerInfoMap"),
   ("read_only_space", 0x00c6d): (92, "SideEffectFreeCallHandlerInfoMap"),
   ("read_only_space", 0x00c95): (92, "NextCallSideEffectFreeCallHandlerInfoMap"),
-  ("read_only_space", 0x00cbd): (126, "SimpleNumberDictionaryMap"),
-  ("read_only_space", 0x00ce5): (117, "SloppyArgumentsElementsMap"),
-  ("read_only_space", 0x00d0d): (146, "SmallOrderedHashMapMap"),
-  ("read_only_space", 0x00d35): (147, "SmallOrderedHashSetMap"),
-  ("read_only_space", 0x00d5d): (148, "SmallOrderedNameDictionaryMap"),
-  ("read_only_space", 0x00d85): (151, "SourceTextModuleMap"),
-  ("read_only_space", 0x00dad): (127, "StringTableMap"),
-  ("read_only_space", 0x00dd5): (152, "SyntheticModuleMap"),
-  ("read_only_space", 0x00dfd): (154, "UncompiledDataWithoutPreparseDataMap"),
-  ("read_only_space", 0x00e25): (153, "UncompiledDataWithPreparseDataMap"),
-  ("read_only_space", 0x00e4d): (179, "WeakArrayListMap"),
-  ("read_only_space", 0x00e75): (119, "EphemeronHashTableMap"),
-  ("read_only_space", 0x00e9d): (162, "EmbedderDataArrayMap"),
-  ("read_only_space", 0x00ec5): (180, "WeakCellMap"),
-  ("read_only_space", 0x00eed): (32, "StringMap"),
-  ("read_only_space", 0x00f15): (41, "ConsOneByteStringMap"),
-  ("read_only_space", 0x00f3d): (33, "ConsStringMap"),
-  ("read_only_space", 0x00f65): (37, "ThinStringMap"),
-  ("read_only_space", 0x00f8d): (35, "SlicedStringMap"),
-  ("read_only_space", 0x00fb5): (43, "SlicedOneByteStringMap"),
-  ("read_only_space", 0x00fdd): (34, "ExternalStringMap"),
-  ("read_only_space", 0x01005): (42, "ExternalOneByteStringMap"),
-  ("read_only_space", 0x0102d): (50, "UncachedExternalStringMap"),
-  ("read_only_space", 0x01055): (0, "InternalizedStringMap"),
-  ("read_only_space", 0x0107d): (2, "ExternalInternalizedStringMap"),
-  ("read_only_space", 0x010a5): (10, "ExternalOneByteInternalizedStringMap"),
-  ("read_only_space", 0x010cd): (18, "UncachedExternalInternalizedStringMap"),
-  ("read_only_space", 0x010f5): (26, "UncachedExternalOneByteInternalizedStringMap"),
-  ("read_only_space", 0x0111d): (58, "UncachedExternalOneByteStringMap"),
-  ("read_only_space", 0x01145): (67, "SelfReferenceMarkerMap"),
+  ("read_only_space", 0x00cbd): (125, "SimpleNumberDictionaryMap"),
+  ("read_only_space", 0x00ce5): (149, "SmallOrderedHashMapMap"),
+  ("read_only_space", 0x00d0d): (150, "SmallOrderedHashSetMap"),
+  ("read_only_space", 0x00d35): (151, "SmallOrderedNameDictionaryMap"),
+  ("read_only_space", 0x00d5d): (152, "SourceTextModuleMap"),
+  ("read_only_space", 0x00d85): (126, "StringTableMap"),
+  ("read_only_space", 0x00dad): (153, "SyntheticModuleMap"),
+  ("read_only_space", 0x00dd5): (155, "UncompiledDataWithoutPreparseDataMap"),
+  ("read_only_space", 0x00dfd): (154, "UncompiledDataWithPreparseDataMap"),
+  ("read_only_space", 0x00e25): (181, "WeakArrayListMap"),
+  ("read_only_space", 0x00e4d): (118, "EphemeronHashTableMap"),
+  ("read_only_space", 0x00e75): (163, "EmbedderDataArrayMap"),
+  ("read_only_space", 0x00e9d): (182, "WeakCellMap"),
+  ("read_only_space", 0x00ec5): (32, "StringMap"),
+  ("read_only_space", 0x00eed): (41, "ConsOneByteStringMap"),
+  ("read_only_space", 0x00f15): (33, "ConsStringMap"),
+  ("read_only_space", 0x00f3d): (37, "ThinStringMap"),
+  ("read_only_space", 0x00f65): (35, "SlicedStringMap"),
+  ("read_only_space", 0x00f8d): (43, "SlicedOneByteStringMap"),
+  ("read_only_space", 0x00fb5): (34, "ExternalStringMap"),
+  ("read_only_space", 0x00fdd): (42, "ExternalOneByteStringMap"),
+  ("read_only_space", 0x01005): (50, "UncachedExternalStringMap"),
+  ("read_only_space", 0x0102d): (0, "InternalizedStringMap"),
+  ("read_only_space", 0x01055): (2, "ExternalInternalizedStringMap"),
+  ("read_only_space", 0x0107d): (10, "ExternalOneByteInternalizedStringMap"),
+  ("read_only_space", 0x010a5): (18, "UncachedExternalInternalizedStringMap"),
+  ("read_only_space", 0x010cd): (26, "UncachedExternalOneByteInternalizedStringMap"),
+  ("read_only_space", 0x010f5): (58, "UncachedExternalOneByteStringMap"),
+  ("read_only_space", 0x0111d): (67, "SelfReferenceMarkerMap"),
+  ("read_only_space", 0x01145): (67, "BasicBlockCountersMarkerMap"),
   ("read_only_space", 0x01179): (95, "EnumCacheMap"),
   ("read_only_space", 0x011c9): (86, "ArrayBoilerplateDescriptionMap"),
-  ("read_only_space", 0x012c5): (98, "InterceptorInfoMap"),
-  ("read_only_space", 0x03335): (71, "PromiseFulfillReactionJobTaskMap"),
-  ("read_only_space", 0x0335d): (72, "PromiseRejectReactionJobTaskMap"),
-  ("read_only_space", 0x03385): (73, "CallableTaskMap"),
-  ("read_only_space", 0x033ad): (74, "CallbackTaskMap"),
-  ("read_only_space", 0x033d5): (75, "PromiseResolveThenableJobTaskMap"),
-  ("read_only_space", 0x033fd): (78, "FunctionTemplateInfoMap"),
-  ("read_only_space", 0x03425): (79, "ObjectTemplateInfoMap"),
-  ("read_only_space", 0x0344d): (80, "AccessCheckInfoMap"),
-  ("read_only_space", 0x03475): (81, "AccessorInfoMap"),
-  ("read_only_space", 0x0349d): (82, "AccessorPairMap"),
-  ("read_only_space", 0x034c5): (83, "AliasedArgumentsEntryMap"),
-  ("read_only_space", 0x034ed): (84, "AllocationMementoMap"),
-  ("read_only_space", 0x03515): (87, "AsmWasmDataMap"),
-  ("read_only_space", 0x0353d): (88, "AsyncGeneratorRequestMap"),
-  ("read_only_space", 0x03565): (89, "BreakPointMap"),
-  ("read_only_space", 0x0358d): (90, "BreakPointInfoMap"),
-  ("read_only_space", 0x035b5): (91, "CachedTemplateObjectMap"),
-  ("read_only_space", 0x035dd): (93, "ClassPositionsMap"),
-  ("read_only_space", 0x03605): (94, "DebugInfoMap"),
-  ("read_only_space", 0x0362d): (97, "FunctionTemplateRareDataMap"),
-  ("read_only_space", 0x03655): (99, "InterpreterDataMap"),
-  ("read_only_space", 0x0367d): (100, "PromiseCapabilityMap"),
-  ("read_only_space", 0x036a5): (101, "PromiseReactionMap"),
-  ("read_only_space", 0x036cd): (102, "PropertyDescriptorObjectMap"),
-  ("read_only_space", 0x036f5): (103, "PrototypeInfoMap"),
-  ("read_only_space", 0x0371d): (104, "ScriptMap"),
-  ("read_only_space", 0x03745): (105, "SourceTextModuleInfoEntryMap"),
-  ("read_only_space", 0x0376d): (106, "StackFrameInfoMap"),
-  ("read_only_space", 0x03795): (107, "StackTraceFrameMap"),
-  ("read_only_space", 0x037bd): (108, "TemplateObjectDescriptionMap"),
-  ("read_only_space", 0x037e5): (109, "Tuple2Map"),
-  ("read_only_space", 0x0380d): (110, "WasmCapiFunctionDataMap"),
-  ("read_only_space", 0x03835): (111, "WasmDebugInfoMap"),
-  ("read_only_space", 0x0385d): (112, "WasmExceptionTagMap"),
-  ("read_only_space", 0x03885): (113, "WasmExportedFunctionDataMap"),
-  ("read_only_space", 0x038ad): (114, "WasmIndirectFunctionTableMap"),
-  ("read_only_space", 0x038d5): (115, "WasmJSFunctionDataMap"),
-  ("read_only_space", 0x038fd): (116, "WasmValueMap"),
-  ("read_only_space", 0x03925): (167, "InternalClassMap"),
-  ("read_only_space", 0x0394d): (175, "SmiPairMap"),
-  ("read_only_space", 0x03975): (174, "SmiBoxMap"),
-  ("read_only_space", 0x0399d): (149, "ExportedSubClassBaseMap"),
-  ("read_only_space", 0x039c5): (150, "ExportedSubClassMap"),
-  ("read_only_space", 0x039ed): (68, "AbstractInternalClassSubclass1Map"),
-  ("read_only_space", 0x03a15): (69, "AbstractInternalClassSubclass2Map"),
-  ("read_only_space", 0x03a3d): (135, "InternalClassWithSmiElementsMap"),
-  ("read_only_space", 0x03a65): (168, "InternalClassWithStructElementsMap"),
-  ("read_only_space", 0x03a8d): (176, "SortStateMap"),
-  ("read_only_space", 0x03ab5): (85, "AllocationSiteWithWeakNextMap"),
-  ("read_only_space", 0x03add): (85, "AllocationSiteWithoutWeakNextMap"),
-  ("read_only_space", 0x03b05): (76, "LoadHandler1Map"),
-  ("read_only_space", 0x03b2d): (76, "LoadHandler2Map"),
-  ("read_only_space", 0x03b55): (76, "LoadHandler3Map"),
-  ("read_only_space", 0x03b7d): (77, "StoreHandler0Map"),
-  ("read_only_space", 0x03ba5): (77, "StoreHandler1Map"),
-  ("read_only_space", 0x03bcd): (77, "StoreHandler2Map"),
-  ("read_only_space", 0x03bf5): (77, "StoreHandler3Map"),
+  ("read_only_space", 0x012b5): (98, "InterceptorInfoMap"),
+  ("read_only_space", 0x03369): (71, "PromiseFulfillReactionJobTaskMap"),
+  ("read_only_space", 0x03391): (72, "PromiseRejectReactionJobTaskMap"),
+  ("read_only_space", 0x033b9): (73, "CallableTaskMap"),
+  ("read_only_space", 0x033e1): (74, "CallbackTaskMap"),
+  ("read_only_space", 0x03409): (75, "PromiseResolveThenableJobTaskMap"),
+  ("read_only_space", 0x03431): (78, "FunctionTemplateInfoMap"),
+  ("read_only_space", 0x03459): (79, "ObjectTemplateInfoMap"),
+  ("read_only_space", 0x03481): (80, "AccessCheckInfoMap"),
+  ("read_only_space", 0x034a9): (81, "AccessorInfoMap"),
+  ("read_only_space", 0x034d1): (82, "AccessorPairMap"),
+  ("read_only_space", 0x034f9): (83, "AliasedArgumentsEntryMap"),
+  ("read_only_space", 0x03521): (84, "AllocationMementoMap"),
+  ("read_only_space", 0x03549): (87, "AsmWasmDataMap"),
+  ("read_only_space", 0x03571): (88, "AsyncGeneratorRequestMap"),
+  ("read_only_space", 0x03599): (89, "BreakPointMap"),
+  ("read_only_space", 0x035c1): (90, "BreakPointInfoMap"),
+  ("read_only_space", 0x035e9): (91, "CachedTemplateObjectMap"),
+  ("read_only_space", 0x03611): (93, "ClassPositionsMap"),
+  ("read_only_space", 0x03639): (94, "DebugInfoMap"),
+  ("read_only_space", 0x03661): (97, "FunctionTemplateRareDataMap"),
+  ("read_only_space", 0x03689): (99, "InterpreterDataMap"),
+  ("read_only_space", 0x036b1): (100, "PromiseCapabilityMap"),
+  ("read_only_space", 0x036d9): (101, "PromiseReactionMap"),
+  ("read_only_space", 0x03701): (102, "PropertyDescriptorObjectMap"),
+  ("read_only_space", 0x03729): (103, "PrototypeInfoMap"),
+  ("read_only_space", 0x03751): (104, "ScriptMap"),
+  ("read_only_space", 0x03779): (105, "SourceTextModuleInfoEntryMap"),
+  ("read_only_space", 0x037a1): (106, "StackFrameInfoMap"),
+  ("read_only_space", 0x037c9): (107, "StackTraceFrameMap"),
+  ("read_only_space", 0x037f1): (108, "TemplateObjectDescriptionMap"),
+  ("read_only_space", 0x03819): (109, "Tuple2Map"),
+  ("read_only_space", 0x03841): (110, "WasmCapiFunctionDataMap"),
+  ("read_only_space", 0x03869): (111, "WasmExceptionTagMap"),
+  ("read_only_space", 0x03891): (112, "WasmExportedFunctionDataMap"),
+  ("read_only_space", 0x038b9): (113, "WasmIndirectFunctionTableMap"),
+  ("read_only_space", 0x038e1): (114, "WasmJSFunctionDataMap"),
+  ("read_only_space", 0x03909): (115, "WasmValueMap"),
+  ("read_only_space", 0x03931): (135, "SloppyArgumentsElementsMap"),
+  ("read_only_space", 0x03959): (171, "OnHeapBasicBlockProfilerDataMap"),
+  ("read_only_space", 0x03981): (168, "InternalClassMap"),
+  ("read_only_space", 0x039a9): (177, "SmiPairMap"),
+  ("read_only_space", 0x039d1): (176, "SmiBoxMap"),
+  ("read_only_space", 0x039f9): (146, "ExportedSubClassBaseMap"),
+  ("read_only_space", 0x03a21): (147, "ExportedSubClassMap"),
+  ("read_only_space", 0x03a49): (68, "AbstractInternalClassSubclass1Map"),
+  ("read_only_space", 0x03a71): (69, "AbstractInternalClassSubclass2Map"),
+  ("read_only_space", 0x03a99): (134, "InternalClassWithSmiElementsMap"),
+  ("read_only_space", 0x03ac1): (169, "InternalClassWithStructElementsMap"),
+  ("read_only_space", 0x03ae9): (148, "ExportedSubClass2Map"),
+  ("read_only_space", 0x03b11): (178, "SortStateMap"),
+  ("read_only_space", 0x03b39): (85, "AllocationSiteWithWeakNextMap"),
+  ("read_only_space", 0x03b61): (85, "AllocationSiteWithoutWeakNextMap"),
+  ("read_only_space", 0x03b89): (76, "LoadHandler1Map"),
+  ("read_only_space", 0x03bb1): (76, "LoadHandler2Map"),
+  ("read_only_space", 0x03bd9): (76, "LoadHandler3Map"),
+  ("read_only_space", 0x03c01): (77, "StoreHandler0Map"),
+  ("read_only_space", 0x03c29): (77, "StoreHandler1Map"),
+  ("read_only_space", 0x03c51): (77, "StoreHandler2Map"),
+  ("read_only_space", 0x03c79): (77, "StoreHandler3Map"),
   ("map_space", 0x00121): (1057, "ExternalMap"),
-  ("map_space", 0x00149): (1073, "JSMessageObjectMap"),
+  ("map_space", 0x00149): (1072, "JSMessageObjectMap"),
 }
 
 # List of known V8 objects.
@@ -381,26 +384,26 @@ KNOWN_OBJECTS = {
   ("read_only_space", 0x011b1): "EmptyObjectBoilerplateDescription",
   ("read_only_space", 0x011bd): "EmptyArrayBoilerplateDescription",
   ("read_only_space", 0x011f1): "EmptyClosureFeedbackCellArray",
-  ("read_only_space", 0x011f9): "EmptySloppyArgumentsElements",
-  ("read_only_space", 0x01209): "EmptySlowElementDictionary",
-  ("read_only_space", 0x0122d): "EmptyOrderedHashMap",
-  ("read_only_space", 0x01241): "EmptyOrderedHashSet",
-  ("read_only_space", 0x01255): "EmptyFeedbackMetadata",
-  ("read_only_space", 0x01261): "EmptyPropertyCell",
-  ("read_only_space", 0x01275): "EmptyPropertyDictionary",
-  ("read_only_space", 0x0129d): "NoOpInterceptorInfo",
-  ("read_only_space", 0x012ed): "EmptyWeakArrayList",
-  ("read_only_space", 0x012f9): "InfinityValue",
-  ("read_only_space", 0x01305): "MinusZeroValue",
-  ("read_only_space", 0x01311): "MinusInfinityValue",
-  ("read_only_space", 0x0131d): "SelfReferenceMarker",
-  ("read_only_space", 0x0135d): "OffHeapTrampolineRelocationInfo",
-  ("read_only_space", 0x01369): "TrampolineTrivialCodeDataContainer",
-  ("read_only_space", 0x01375): "TrampolinePromiseRejectionCodeDataContainer",
-  ("read_only_space", 0x01381): "GlobalThisBindingScopeInfo",
-  ("read_only_space", 0x013b9): "EmptyFunctionScopeInfo",
-  ("read_only_space", 0x013e1): "NativeScopeInfo",
-  ("read_only_space", 0x013fd): "HashSeed",
+  ("read_only_space", 0x011f9): "EmptySlowElementDictionary",
+  ("read_only_space", 0x0121d): "EmptyOrderedHashMap",
+  ("read_only_space", 0x01231): "EmptyOrderedHashSet",
+  ("read_only_space", 0x01245): "EmptyFeedbackMetadata",
+  ("read_only_space", 0x01251): "EmptyPropertyCell",
+  ("read_only_space", 0x01265): "EmptyPropertyDictionary",
+  ("read_only_space", 0x0128d): "NoOpInterceptorInfo",
+  ("read_only_space", 0x012dd): "EmptyWeakArrayList",
+  ("read_only_space", 0x012e9): "InfinityValue",
+  ("read_only_space", 0x012f5): "MinusZeroValue",
+  ("read_only_space", 0x01301): "MinusInfinityValue",
+  ("read_only_space", 0x0130d): "SelfReferenceMarker",
+  ("read_only_space", 0x0134d): "BasicBlockCountersMarker",
+  ("read_only_space", 0x01391): "OffHeapTrampolineRelocationInfo",
+  ("read_only_space", 0x0139d): "TrampolineTrivialCodeDataContainer",
+  ("read_only_space", 0x013a9): "TrampolinePromiseRejectionCodeDataContainer",
+  ("read_only_space", 0x013b5): "GlobalThisBindingScopeInfo",
+  ("read_only_space", 0x013ed): "EmptyFunctionScopeInfo",
+  ("read_only_space", 0x01415): "NativeScopeInfo",
+  ("read_only_space", 0x01431): "HashSeed",
   ("old_space", 0x00121): "ArgumentsIteratorAccessor",
   ("old_space", 0x00165): "ArrayLengthAccessor",
   ("old_space", 0x001a9): "BoundFunctionLengthAccessor",
diff --git a/chromium/v8/tools/v8windbg/base/utilities.cc b/chromium/v8/tools/v8windbg/base/utilities.cc
index a59e95f46fd..1f0e2bc6708 100644
--- a/chromium/v8/tools/v8windbg/base/utilities.cc
+++ b/chromium/v8/tools/v8windbg/base/utilities.cc
@@ -133,6 +133,15 @@ HRESULT UnboxULong64(IModelObject* object, ULONG64* value, bool convert) {
   return S_OK;
 }
 
+HRESULT GetInt32(IDebugHostConstant* object, int* value) {
+  variant_t variant;
+  RETURN_IF_FAIL(object->GetValue(&variant));
+
+  if (variant.vt != VT_I4) return E_FAIL;
+  *value = variant.ullVal;
+  return S_OK;
+}
+
 HRESULT CreateInt32(int value, IModelObject** pp_int) {
   HRESULT hr = S_OK;
   *pp_int = nullptr;
diff --git a/chromium/v8/tools/v8windbg/base/utilities.h b/chromium/v8/tools/v8windbg/base/utilities.h
index e26bb287804..06af6c35875 100644
--- a/chromium/v8/tools/v8windbg/base/utilities.h
+++ b/chromium/v8/tools/v8windbg/base/utilities.h
@@ -55,6 +55,8 @@ HRESULT CreateULong64(ULONG64 value, IModelObject** pp_int);
 HRESULT UnboxULong64(IModelObject* object, ULONG64* value,
                      bool convert = false);
 
+HRESULT GetInt32(IDebugHostConstant* object, int* value);
+
 HRESULT CreateInt32(int value, IModelObject** pp_int);
 
 HRESULT CreateUInt32(uint32_t value, IModelObject** pp_int);
diff --git a/chromium/v8/tools/v8windbg/src/object-inspection.cc b/chromium/v8/tools/v8windbg/src/object-inspection.cc
index ce0370a697f..6f90614bd5c 100644
--- a/chromium/v8/tools/v8windbg/src/object-inspection.cc
+++ b/chromium/v8/tools/v8windbg/src/object-inspection.cc
@@ -585,6 +585,79 @@ IFACEMETHODIMP V8LocalValueProperty::SetValue(
   return E_NOTIMPL;
 }
 
+IFACEMETHODIMP V8InternalCompilerNodeIdProperty::GetValue(
+    PCWSTR pwsz_key, IModelObject* p_v8_compiler_node_instance,
+    IModelObject** pp_value) noexcept {
+  WRL::ComPtr<IModelObject> sp_bit_field;
+  RETURN_IF_FAIL(p_v8_compiler_node_instance->GetRawValue(
+      SymbolKind::SymbolField, L"bit_field_", RawSearchNone, &sp_bit_field));
+
+  uint64_t bit_field_value;
+  RETURN_IF_FAIL(
+      UnboxULong64(sp_bit_field.Get(), &bit_field_value, true /*convert*/));
+
+  WRL::ComPtr<IDebugHostContext> sp_host_context;
+  RETURN_IF_FAIL(p_v8_compiler_node_instance->GetContext(&sp_host_context));
+
+  WRL::ComPtr<IDebugHostType> sp_id_field_type;
+  RETURN_IF_FAIL(Extension::Current()
+                     ->GetV8Module(sp_host_context)
+                     ->FindTypeByName(L"v8::internal::compiler::Node::IdField",
+                                      &sp_id_field_type));
+
+  // Get 2nd template parameter as 24 in class.
+  // v8::base::BitField<v8::internal::compiler::NodeId, 0, 24>.
+  bool is_generic;
+  RETURN_IF_FAIL(sp_id_field_type->IsGeneric(&is_generic));
+  if (!is_generic) return E_FAIL;
+
+  WRL::ComPtr<IDebugHostSymbol> sp_k_size_arg;
+  RETURN_IF_FAIL(sp_id_field_type->GetGenericArgumentAt(2, &sp_k_size_arg));
+
+  WRL::ComPtr<IDebugHostConstant> sp_k_size_constant;
+  RETURN_IF_FAIL(sp_k_size_arg.As(&sp_k_size_constant));
+
+  int k_size;
+  RETURN_IF_FAIL(GetInt32(sp_k_size_constant.Get(), &k_size));
+
+  // Compute node_id.
+  uint32_t node_id = bit_field_value & (0xFFFFFFFF >> k_size);
+  RETURN_IF_FAIL(CreateUInt32(node_id, pp_value));
+
+  return S_OK;
+}
+
+IFACEMETHODIMP V8InternalCompilerNodeIdProperty::SetValue(
+    PCWSTR /*pwsz_key*/, IModelObject* /*p_process_instance*/,
+    IModelObject* /*p_value*/) noexcept {
+  return E_NOTIMPL;
+}
+
+IFACEMETHODIMP V8InternalCompilerBitsetNameProperty::GetValue(
+    PCWSTR pwsz_key, IModelObject* p_v8_compiler_type_instance,
+    IModelObject** pp_value) noexcept {
+  WRL::ComPtr<IModelObject> sp_payload;
+  RETURN_IF_FAIL(p_v8_compiler_type_instance->GetRawValue(
+      SymbolKind::SymbolField, L"payload_", RawSearchNone, &sp_payload));
+
+  uint64_t payload_value;
+  RETURN_IF_FAIL(
+      UnboxULong64(sp_payload.Get(), &payload_value, true /*convert*/));
+
+  const char* bitset_name = ::BitsetName(payload_value);
+  if (!bitset_name) return E_FAIL;
+  std::string name(bitset_name);
+  RETURN_IF_FAIL(CreateString(ConvertToU16String(name), pp_value));
+
+  return S_OK;
+}
+
+IFACEMETHODIMP V8InternalCompilerBitsetNameProperty::SetValue(
+    PCWSTR /*pwsz_key*/, IModelObject* /*p_process_instance*/,
+    IModelObject* /*p_value*/) noexcept {
+  return E_NOTIMPL;
+}
+
 constexpr wchar_t usage[] =
     LR"(Invalid arguments.
 First argument should be a uint64 representing the tagged value to investigate.
diff --git a/chromium/v8/tools/v8windbg/src/object-inspection.h b/chromium/v8/tools/v8windbg/src/object-inspection.h
index 27283ca5569..a280b05cade 100644
--- a/chromium/v8/tools/v8windbg/src/object-inspection.h
+++ b/chromium/v8/tools/v8windbg/src/object-inspection.h
@@ -245,6 +245,38 @@ class V8LocalValueProperty
    IModelObject* /*p_value*/);
 };
 
+// The implemention of the "NodeId" getter for v8::internal::compiler::Node
+// type.
+class V8InternalCompilerNodeIdProperty
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IModelPropertyAccessor> {
+ public:
+  IFACEMETHOD(GetValue)
+  (PCWSTR pwsz_key, IModelObject* p_v8_object_instance,
+   IModelObject** pp_value);
+
+  IFACEMETHOD(SetValue)
+  (PCWSTR /*pwsz_key*/, IModelObject* /*p_process_instance*/,
+   IModelObject* /*p_value*/);
+};
+
+// The implemention of the "bitset_name" getter for v8::internal::compiler::Type
+// type.
+class V8InternalCompilerBitsetNameProperty
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IModelPropertyAccessor> {
+ public:
+  IFACEMETHOD(GetValue)
+  (PCWSTR pwsz_key, IModelObject* p_v8_compiler_type_instance,
+   IModelObject** pp_value);
+
+  IFACEMETHOD(SetValue)
+  (PCWSTR /*pwsz_key*/, IModelObject* /*p_process_instance*/,
+   IModelObject* /*p_value*/);
+};
+
 // A way that someone can directly inspect a tagged value, even if that value
 // isn't in memory (from a register, or the user's imagination, etc.).
 class InspectV8ObjectMethod
diff --git a/chromium/v8/tools/v8windbg/src/v8-debug-helper-interop.cc b/chromium/v8/tools/v8windbg/src/v8-debug-helper-interop.cc
index 4a8dcc9add7..0767ff5f09e 100644
--- a/chromium/v8/tools/v8windbg/src/v8-debug-helper-interop.cc
+++ b/chromium/v8/tools/v8windbg/src/v8-debug-helper-interop.cc
@@ -155,3 +155,5 @@ std::vector<std::u16string> ListObjectClasses() {
   }
   return result;
 }
+
+const char* BitsetName(uint64_t payload) { return d::BitsetName(payload); }
diff --git a/chromium/v8/tools/v8windbg/src/v8-debug-helper-interop.h b/chromium/v8/tools/v8windbg/src/v8-debug-helper-interop.h
index 96bd59b30ea..9208f098327 100644
--- a/chromium/v8/tools/v8windbg/src/v8-debug-helper-interop.h
+++ b/chromium/v8/tools/v8windbg/src/v8-debug-helper-interop.h
@@ -135,4 +135,6 @@ inline uint64_t ExpandCompressedPointer(uint32_t ptr) { return ptr; }
 
 std::vector<std::u16string> ListObjectClasses();
 
+const char* BitsetName(uint64_t payload);
+
 #endif  // V8_TOOLS_V8WINDBG_SRC_V8_DEBUG_HELPER_INTEROP_H_
diff --git a/chromium/v8/tools/v8windbg/src/v8windbg-extension.cc b/chromium/v8/tools/v8windbg/src/v8windbg-extension.cc
index 68c90d2833b..58a520cff1f 100644
--- a/chromium/v8/tools/v8windbg/src/v8windbg-extension.cc
+++ b/chromium/v8/tools/v8windbg/src/v8windbg-extension.cc
@@ -215,7 +215,8 @@ HRESULT Extension::Initialize() {
         &sp_object_type_signature));
     RETURN_IF_FAIL(sp_data_model_manager->RegisterModelForTypeSignature(
         sp_object_type_signature.Get(), sp_object_data_model_.Get()));
-    registered_object_types_.push_back(sp_object_type_signature);
+    registered_types_.push_back(
+        {sp_object_type_signature.Get(), sp_object_data_model_.Get()});
   }
 
   // Create an instance of the DataModel parent for custom iterable fields.
@@ -244,7 +245,7 @@ HRESULT Extension::Initialize() {
         sp_debug_host_symbols->CreateTypeSignature(name, nullptr, &signature));
     RETURN_IF_FAIL(sp_data_model_manager->RegisterModelForTypeSignature(
         signature.Get(), sp_local_data_model_.Get()));
-    registered_handle_types_.push_back(signature);
+    registered_types_.push_back({signature.Get(), sp_local_data_model_.Get()});
   }
 
   // Add the 'Value' property to the parent model.
@@ -279,6 +280,46 @@ HRESULT Extension::Initialize() {
   RETURN_IF_FAIL(OverrideLocalsGetter(stack_frame.Get(), L"Parameters",
                                       /*is_parameters=*/true));
 
+  // Add node_id property for v8::internal::compiler::Node.
+  RETURN_IF_FAIL(
+      RegisterAndAddPropertyForClass<V8InternalCompilerNodeIdProperty>(
+          L"v8::internal::compiler::Node", L"node_id",
+          sp_compiler_node_data_model_));
+
+  // Add bitset_name property for v8::internal::compiler::Type.
+  RETURN_IF_FAIL(
+      RegisterAndAddPropertyForClass<V8InternalCompilerBitsetNameProperty>(
+          L"v8::internal::compiler::Type", L"bitset_name",
+          sp_compiler_type_data_model_));
+
+  return S_OK;
+}
+
+template <class PropertyClass>
+HRESULT Extension::RegisterAndAddPropertyForClass(
+    const wchar_t* class_name, const wchar_t* property_name,
+    WRL::ComPtr<IModelObject> sp_data_model) {
+  // Create an instance of the DataModel parent class.
+  auto instance_data_model{WRL::Make<V8LocalDataModel>()};
+  RETURN_IF_FAIL(sp_data_model_manager->CreateDataModelObject(
+      instance_data_model.Get(), &sp_data_model));
+
+  // Register that parent model.
+  WRL::ComPtr<IDebugHostTypeSignature> class_signature;
+  RETURN_IF_FAIL(sp_debug_host_symbols->CreateTypeSignature(class_name, nullptr,
+                                                            &class_signature));
+  RETURN_IF_FAIL(sp_data_model_manager->RegisterModelForTypeSignature(
+      class_signature.Get(), sp_data_model.Get()));
+  registered_types_.push_back({class_signature.Get(), sp_data_model.Get()});
+
+  // Add the property to the parent model.
+  auto property{WRL::Make<PropertyClass>()};
+  WRL::ComPtr<IModelObject> sp_property_model;
+  RETURN_IF_FAIL(CreateProperty(sp_data_model_manager.Get(), property.Get(),
+                                &sp_property_model));
+  RETURN_IF_FAIL(
+      sp_data_model->SetKey(property_name, sp_property_model.Get(), nullptr));
+
   return S_OK;
 }
 
@@ -318,18 +359,24 @@ Extension::PropertyOverride::PropertyOverride(const PropertyOverride&) =
 Extension::PropertyOverride& Extension::PropertyOverride::operator=(
     const PropertyOverride&) = default;
 
+Extension::RegistrationType::RegistrationType() = default;
+Extension::RegistrationType::RegistrationType(
+    IDebugHostTypeSignature* sp_signature, IModelObject* sp_data_model)
+    : sp_signature(sp_signature), sp_data_model(sp_data_model) {}
+Extension::RegistrationType::~RegistrationType() = default;
+Extension::RegistrationType::RegistrationType(const RegistrationType&) =
+    default;
+Extension::RegistrationType& Extension::RegistrationType::operator=(
+    const RegistrationType&) = default;
+
 Extension::~Extension() {
   sp_debug_host_extensibility->DestroyFunctionAlias(pcur_isolate);
   sp_debug_host_extensibility->DestroyFunctionAlias(plist_chunks);
   sp_debug_host_extensibility->DestroyFunctionAlias(pv8_object);
 
-  for (const auto& registered : registered_object_types_) {
-    sp_data_model_manager->UnregisterModelForTypeSignature(
-        sp_object_data_model_.Get(), registered.Get());
-  }
-  for (const auto& registered : registered_handle_types_) {
+  for (const auto& registered : registered_types_) {
     sp_data_model_manager->UnregisterModelForTypeSignature(
-        sp_local_data_model_.Get(), registered.Get());
+        registered.sp_data_model.Get(), registered.sp_signature.Get());
   }
 
   for (const auto& override : overridden_properties_) {
diff --git a/chromium/v8/tools/v8windbg/src/v8windbg-extension.h b/chromium/v8/tools/v8windbg/src/v8windbg-extension.h
index d54f43c847e..46331611523 100644
--- a/chromium/v8/tools/v8windbg/src/v8windbg-extension.h
+++ b/chromium/v8/tools/v8windbg/src/v8windbg-extension.h
@@ -46,6 +46,11 @@ class Extension {
   HRESULT OverrideLocalsGetter(IModelObject* parent, const wchar_t* key_name,
                                bool is_parameters);
 
+  template <class PropertyClass>
+  HRESULT RegisterAndAddPropertyForClass(
+      const wchar_t* class_name, const wchar_t* property_name,
+      WRL::ComPtr<IModelObject> sp_data_model);
+
   // A property that has been overridden by this extension. The original value
   // must be put back in place during ~Extension.
   struct PropertyOverride {
@@ -62,20 +67,32 @@ class Extension {
     WRL::ComPtr<IKeyStore> original_metadata;
   };
 
+  struct RegistrationType {
+    RegistrationType();
+    RegistrationType(IDebugHostTypeSignature* sp_signature,
+                     IModelObject* sp_data_model);
+    ~RegistrationType();
+    RegistrationType(const RegistrationType&);
+    RegistrationType& operator=(const RegistrationType&);
+
+    WRL::ComPtr<IDebugHostTypeSignature> sp_signature;
+    WRL::ComPtr<IModelObject> sp_data_model;
+  };
+
   static std::unique_ptr<Extension> current_extension_;
 
   WRL::ComPtr<IModelObject> sp_object_data_model_;
   WRL::ComPtr<IModelObject> sp_local_data_model_;
+  WRL::ComPtr<IModelObject> sp_compiler_node_data_model_;
+  WRL::ComPtr<IModelObject> sp_compiler_type_data_model_;
   WRL::ComPtr<IModelObject> sp_indexed_field_model_;
 
   WRL::ComPtr<IDebugHostModule> sp_v8_module_;
   std::unordered_map<std::u16string, WRL::ComPtr<IDebugHostType>>
       cached_v8_module_types_;
-  std::vector<WRL::ComPtr<IDebugHostTypeSignature>> registered_object_types_;
-  std::vector<WRL::ComPtr<IDebugHostTypeSignature>> registered_handle_types_;
+  std::vector<RegistrationType> registered_types_;
   std::vector<PropertyOverride> overridden_properties_;
   WRL::ComPtr<IDebugHostContext> sp_v8_module_ctx_;
   ULONG v8_module_proc_id_;
 };
-
 #endif  // V8_TOOLS_V8WINDBG_SRC_V8WINDBG_EXTENSION_H_
diff --git a/chromium/v8/tools/wasm/update-wasm-spec-tests.sh b/chromium/v8/tools/wasm/update-wasm-spec-tests.sh
index b3e9185c4df..8a63f94368e 100755
--- a/chromium/v8/tools/wasm/update-wasm-spec-tests.sh
+++ b/chromium/v8/tools/wasm/update-wasm-spec-tests.sh
@@ -95,7 +95,10 @@ for repo in ${repos}; do
       log_and_run ./run.py --wasm ../../interpreter/wasm ${rel_filename} --out _build 2> /dev/null
     fi
   done
-  log_and_run cp _build/*.js ${SPEC_TEST_DIR}/tests/proposals/${repo}/
+
+  if ls _build/*.js > /dev/null; then
+    log_and_run cp _build/*.js ${SPEC_TEST_DIR}/tests/proposals/${repo}/
+  fi
 
   echo ">> Process js-api tests"
   log_and_run mkdir ${JS_API_TEST_DIR}/tests/proposals/${repo}
diff --git a/chromium/v8/tools/whitespace.txt b/chromium/v8/tools/whitespace.txt
index 4668daa518f..94f29d13401 100644
--- a/chromium/v8/tools/whitespace.txt
+++ b/chromium/v8/tools/whitespace.txt
@@ -8,7 +8,7 @@ The doubles heard this and started to unbox.
 The Smi looked at them when a crazy v8-autoroll account showed up...
 The autoroller bought a round of Himbeerbrause. Suddenly.....
 The bartender starts to shake the bottles.....................
-I can't add trailing whitespaces, so I'm adding this line.....
+I can't add trailing whitespaces, so I'm adding this line......
 I'm starting to think that just adding trailing whitespaces might not be bad.
 
 Because whitespaces are not that funny.....
diff --git a/chromium/v8/tools/zone-stats/categories.js b/chromium/v8/tools/zone-stats/categories.js
new file mode 100644
index 00000000000..96c4e32eaf7
--- /dev/null
+++ b/chromium/v8/tools/zone-stats/categories.js
@@ -0,0 +1,129 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+const UNCLASSIFIED_CATEGORY = 'unclassified';
+const UNCLASSIFIED_CATEGORY_NAME = 'Unclassified';
+
+// Categories for zones.
+export const CATEGORIES = new Map([
+  [
+    'parser', new Set([
+      'AstStringConstants',
+      'ParseInfo',
+      'Parser',
+    ])
+  ],
+  [
+    'misc', new Set([
+      'Run',
+      'CanonicalHandleScope',
+      'Temporary scoped zone',
+      'UpdateFieldType',
+    ])
+  ],
+  [
+    'interpreter', new Set([
+      'InterpreterCompilationJob',
+    ])
+  ],
+  [
+    'regexp', new Set([
+      'CompileIrregexp',
+    ])
+  ],
+  [
+    'compiler-huge', new Set([
+      'graph-zone',
+      'instruction-zone',
+      'pipeline-compilation-job-zone',
+      'register-allocation-zone',
+      'register-allocator-verifier-zone',
+    ])
+  ],
+  [
+    'compiler-other', new Set([
+      'Compile',
+      'V8.TFAllocateFPRegisters',
+      'V8.TFAllocateGeneralRegisters',
+      'V8.TFAssembleCode',
+      'V8.TFAssignSpillSlots',
+      'V8.TFBuildLiveRangeBundles',
+      'V8.TFBuildLiveRanges',
+      'V8.TFBytecodeGraphBuilder',
+      'V8.TFCommitAssignment',
+      'V8.TFConnectRanges',
+      'V8.TFControlFlowOptimization',
+      'V8.TFDecideSpillingMode',
+      'V8.TFDecompressionOptimization',
+      'V8.TFEarlyOptimization',
+      'V8.TFEarlyTrimming',
+      'V8.TFEffectLinearization',
+      'V8.TFEscapeAnalysis',
+      'V8.TFFinalizeCode',
+      'V8.TFFrameElision',
+      'V8.TFGenericLowering',
+      'V8.TFHeapBrokerInitialization',
+      'V8.TFInlining',
+      'V8.TFJumpThreading',
+      'V8.TFLateGraphTrimming',
+      'V8.TFLateOptimization',
+      'V8.TFLoadElimination',
+      'V8.TFLocateSpillSlots',
+      'V8.TFLoopPeeling',
+      'V8.TFMachineOperatorOptimization',
+      'V8.TFMeetRegisterConstraints',
+      'V8.TFMemoryOptimization',
+      'V8.TFOptimizeMoves',
+      'V8.TFPopulatePointerMaps',
+      'V8.TFResolveControlFlow',
+      'V8.TFResolvePhis',
+      'V8.TFScheduling',
+      'V8.TFSelectInstructions',
+      'V8.TFSerializeMetadata',
+      'V8.TFSimplifiedLowering',
+      'V8.TFStoreStoreElimination',
+      'V8.TFTypedLowering',
+      'V8.TFTyper',
+      'V8.TFUntyper',
+      'V8.TFVerifyGraph',
+      'ValidatePendingAssessment',
+      'codegen-zone',
+    ])
+  ],
+  [UNCLASSIFIED_CATEGORY, new Set()],
+]);
+
+// Maps category to description text that is shown in html.
+export const CATEGORY_NAMES = new Map([
+  ['parser', 'Parser'],
+  ['misc', 'Misc'],
+  ['interpreter', 'Ignition'],
+  ['regexp', 'Regexp compiler'],
+  ['compiler-huge', 'TurboFan (huge zones)'],
+  ['compiler-other', 'TurboFan (other zones)'],
+  [UNCLASSIFIED_CATEGORY, UNCLASSIFIED_CATEGORY_NAME],
+]);
+
+function buildZoneToCategoryMap() {
+  const map = new Map();
+  for (let [category, zone_names] of CATEGORIES.entries()) {
+    for (let zone_name of zone_names) {
+      if (map.has(zone_name)) {
+        console.error("Zone belongs to multiple categories: " + zone_name);
+      } else {
+        map.set(zone_name, category);
+      }
+    }
+  }
+  return map;
+}
+
+const CATEGORY_BY_ZONE = buildZoneToCategoryMap();
+
+// Maps zone name to category.
+export function categoryByZoneName(zone_name) {
+  const category = CATEGORY_BY_ZONE.get(zone_name);
+  if (category !== undefined) return category;
+  return UNCLASSIFIED_CATEGORY;
+}
diff --git a/chromium/v8/tools/zone-stats/details-selection-template.html b/chromium/v8/tools/zone-stats/details-selection-template.html
new file mode 100644
index 00000000000..ef1e2f68b9b
--- /dev/null
+++ b/chromium/v8/tools/zone-stats/details-selection-template.html
@@ -0,0 +1,146 @@
+<!-- Copyright 2020 the V8 project authors. All rights reserved.
+Use of this source code is governed by a BSD-style license that can be
+found in the LICENSE file. -->
+<style>
+#dataSelectionSection {
+  display: none;
+}
+
+.box {
+  border-left: dashed 1px #666666;
+  border-right: dashed 1px #666666;
+  border-bottom: dashed 1px #666666;
+  padding: 10px;
+  overflow: hidden;
+  position: relative;
+}
+
+.box:nth-of-type(1) {
+  border-top: dashed 1px #666666;
+  border-radius: 5px 5px 0px 0px;
+}
+
+.box:last-of-type {
+    border-radius: 0px 0px 5px 5px;
+}
+
+.box > ul {
+  margin: 0px;
+  padding: 0px;
+}
+
+.box > ul > li {
+  display: inline-block;
+}
+
+.box > ul > li:not(:first-child) {
+  margin-left: 10px;
+}
+
+.box > ul > li:first-child {
+  font-weight: bold;
+}
+
+.zonesSelectBox {
+  position: relative;
+  overflow: hidden;
+  float: left;
+  padding: 0px 5px 2px 0px;
+  margin: 3px;
+  border-radius: 3px;
+}
+
+.zonesSelectBox > label {
+  font-size: xx-small;
+}
+
+.zonesSelectBox > input {
+  vertical-align: middle;
+}
+
+.percentBackground {
+  position: absolute;
+  width: 200%;
+  height: 100%;
+  left: 0%;
+  top: 0px;
+  margin-left: -100%;
+  transition: all 1s ease-in-out;
+}
+
+.zonesSelectBox > .percentBackground  {
+  background: linear-gradient(90deg, #68b0f7 50%, #b3d9ff 50%);
+  z-index: -1;
+}
+.box > .percentBackground  {
+  background: linear-gradient(90deg, #e0edfe 50%, #fff 50%);
+  z-index: -2;
+}
+
+#categories {
+  margin-top: 10px;
+}
+
+#category-filter {
+  text-align: right;
+  width: 50px;
+}
+
+</style>
+<section id="dataSelectionSection">
+  <h2>Data selection</h2>
+  <ul>
+    <li>
+      <label for="isolate-select">
+        Isolate
+      </label>
+      <select id="isolate-select">
+        <option>No data</option>
+      </select>
+    </li>
+    <li>
+      <label for="data-view-select">
+        Data view
+      </label>
+      <select id="data-view-select">
+        <option>No data</option>
+      </select>
+    </li>
+    <li>
+      <label for="show-totals-select">
+        Show total allocated/used zone memory
+      </label>
+      <input type="checkbox" id="show-totals-select" checked>
+    </li>
+    <li>
+      <label for="data-kind-select">
+        Data kind
+      </label>
+      <select id="data-kind-select">
+        <option>No data</option>
+      </select>
+    </li>
+    <li>
+      <label for="time-start-select">
+        Time start
+      </label>
+      <input type="number" id="time-start-select" value="0">ms</input>
+    </li>
+    <li>
+      <label for="time-end-select">
+        Time end
+      </label>
+      <input type="number" id="time-end-select" value="0">ms</input>
+    </li>
+    <li>
+      <label for="memory-usage-sample-select">
+        Memory usage sample (at a specific time in ms)
+      </label>
+      <select id="memory-usage-sample-select">
+        <option>No data</option>
+      </select>
+    </li>
+  </ul>
+
+  <div id="categories"></div>
+</section>
diff --git a/chromium/v8/tools/zone-stats/details-selection.js b/chromium/v8/tools/zone-stats/details-selection.js
new file mode 100644
index 00000000000..b25a11337a3
--- /dev/null
+++ b/chromium/v8/tools/zone-stats/details-selection.js
@@ -0,0 +1,365 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+'use strict';
+
+import {CATEGORIES, CATEGORY_NAMES, categoryByZoneName} from './categories.js';
+
+export const VIEW_TOTALS = 'by-totals';
+export const VIEW_BY_ZONE_NAME = 'by-zone-name';
+export const VIEW_BY_ZONE_CATEGORY = 'by-zone-category';
+
+export const KIND_ALLOCATED_MEMORY = 'kind-detailed-allocated';
+export const KIND_USED_MEMORY = 'kind-detailed-used';
+
+defineCustomElement('details-selection', (templateText) =>
+ class DetailsSelection extends HTMLElement {
+  constructor() {
+    super();
+    const shadowRoot = this.attachShadow({mode: 'open'});
+    shadowRoot.innerHTML = templateText;
+    this.isolateSelect.addEventListener(
+        'change', e => this.handleIsolateChange(e));
+    this.dataViewSelect.addEventListener(
+        'change', e => this.notifySelectionChanged(e));
+    this.dataKindSelect.addEventListener(
+        'change', e => this.notifySelectionChanged(e));
+    this.showTotalsSelect.addEventListener(
+        'change', e => this.notifySelectionChanged(e));
+    this.memoryUsageSampleSelect.addEventListener(
+        'change', e => this.notifySelectionChanged(e));
+    this.timeStartSelect.addEventListener(
+        'change', e => this.notifySelectionChanged(e));
+    this.timeEndSelect.addEventListener(
+        'change', e => this.notifySelectionChanged(e));
+  }
+
+  connectedCallback() {
+    for (let category of CATEGORIES.keys()) {
+      this.$('#categories').appendChild(this.buildCategory(category));
+    }
+  }
+
+  set data(value) {
+    this._data = value;
+    this.dataChanged();
+  }
+
+  get data() {
+    return this._data;
+  }
+
+  get selectedIsolate() {
+    return this._data[this.selection.isolate];
+  }
+
+  get selectedData() {
+    console.assert(this.data, 'invalid data');
+    console.assert(this.selection, 'invalid selection');
+    const time = this.selection.time;
+    return this.selectedIsolate.samples.get(time);
+  }
+
+  $(id) {
+    return this.shadowRoot.querySelector(id);
+  }
+
+  querySelectorAll(query) {
+    return this.shadowRoot.querySelectorAll(query);
+  }
+
+  get dataViewSelect() {
+    return this.$('#data-view-select');
+  }
+
+  get dataKindSelect() {
+    return this.$('#data-kind-select');
+  }
+
+  get isolateSelect() {
+    return this.$('#isolate-select');
+  }
+
+  get memoryUsageSampleSelect() {
+    return this.$('#memory-usage-sample-select');
+  }
+
+  get showTotalsSelect() {
+    return this.$('#show-totals-select');
+  }
+
+  get timeStartSelect() {
+    return this.$('#time-start-select');
+  }
+
+  get timeEndSelect() {
+    return this.$('#time-end-select');
+  }
+
+  buildCategory(name) {
+    const div = document.createElement('div');
+    div.id = name;
+    div.classList.add('box');
+    const ul = document.createElement('ul');
+    div.appendChild(ul);
+    const name_li = document.createElement('li');
+    ul.appendChild(name_li);
+    name_li.innerHTML = CATEGORY_NAMES.get(name);
+    const percent_li = document.createElement('li');
+    ul.appendChild(percent_li);
+    percent_li.innerHTML = '0%';
+    percent_li.id = name + 'PercentContent';
+    const all_li = document.createElement('li');
+    ul.appendChild(all_li);
+    const all_button = document.createElement('button');
+    all_li.appendChild(all_button);
+    all_button.innerHTML = 'All';
+    all_button.addEventListener('click', e => this.selectCategory(name));
+    const none_li = document.createElement('li');
+    ul.appendChild(none_li);
+    const none_button = document.createElement('button');
+    none_li.appendChild(none_button);
+    none_button.innerHTML = 'None';
+    none_button.addEventListener('click', e => this.unselectCategory(name));
+    const innerDiv = document.createElement('div');
+    div.appendChild(innerDiv);
+    innerDiv.id = name + 'Content';
+    const percentDiv = document.createElement('div');
+    div.appendChild(percentDiv);
+    percentDiv.className = 'percentBackground';
+    percentDiv.id = name + 'PercentBackground';
+    return div;
+  }
+
+  dataChanged() {
+    this.selection = {categories: {}, zones: new Map()};
+    this.resetUI(true);
+    this.populateIsolateSelect();
+    this.handleIsolateChange();
+    this.$('#dataSelectionSection').style.display = 'block';
+  }
+
+  populateIsolateSelect() {
+    let isolates = Object.entries(this.data);
+    // Sort by peak heap memory consumption.
+    isolates.sort((a, b) => b[1].peakAllocatedMemory - a[1].peakAllocatedMemory);
+    this.populateSelect(
+        '#isolate-select', isolates, (key, isolate) => isolate.getLabel());
+  }
+
+  resetUI(resetIsolateSelect) {
+    if (resetIsolateSelect) removeAllChildren(this.isolateSelect);
+
+    removeAllChildren(this.dataViewSelect);
+    removeAllChildren(this.dataKindSelect);
+    removeAllChildren(this.memoryUsageSampleSelect);
+    this.clearCategories();
+  }
+
+  handleIsolateChange(e) {
+    this.selection.isolate = this.isolateSelect.value;
+    if (this.selection.isolate.length === 0) {
+      this.selection.isolate = null;
+      return;
+    }
+    this.resetUI(false);
+    this.populateSelect(
+        '#data-view-select', [
+          [VIEW_TOTALS, 'Total memory usage'],
+          [VIEW_BY_ZONE_NAME, 'Selected zones types'],
+          [VIEW_BY_ZONE_CATEGORY, 'Selected zone categories'],
+        ],
+        (key, label) => label, VIEW_TOTALS);
+    this.populateSelect(
+      '#data-kind-select', [
+        [KIND_ALLOCATED_MEMORY, 'Allocated memory per zone'],
+        [KIND_USED_MEMORY, 'Used memory per zone'],
+      ],
+      (key, label) => label, KIND_ALLOCATED_MEMORY);
+
+    this.populateSelect(
+      '#memory-usage-sample-select',
+      [...this.selectedIsolate.samples.entries()].filter(([time, sample]) => {
+        // Remove samples that does not have detailed per-zone data.
+        return sample.zones !== undefined;
+      }),
+      (time, sample, index) => {
+        return ((index + ': ').padStart(6, '\u00A0') +
+          formatSeconds(time).padStart(8, '\u00A0') + ' ' +
+          formatBytes(sample.allocated).padStart(12, '\u00A0'));
+      },
+      this.selectedIsolate.peakUsageTime);
+
+    this.timeStartSelect.value = this.selectedIsolate.start;
+    this.timeEndSelect.value = this.selectedIsolate.end;
+
+    this.populateCategories();
+    this.notifySelectionChanged();
+  }
+
+  notifySelectionChanged(e) {
+    if (!this.selection.isolate) return;
+
+    this.selection.data_view = this.dataViewSelect.value;
+    this.selection.data_kind = this.dataKindSelect.value;
+    this.selection.categories = Object.create(null);
+    this.selection.zones = new Map();
+    this.$('#categories').style.display = 'none';
+    for (let category of CATEGORIES.keys()) {
+      const selected = this.selectedInCategory(category);
+      if (selected.length > 0) this.selection.categories[category] = selected;
+      for (const zone_name of selected) {
+        this.selection.zones.set(zone_name, category);
+      }
+    }
+    this.$('#categories').style.display = 'block';
+    this.selection.category_names = CATEGORY_NAMES;
+    this.selection.show_totals = this.showTotalsSelect.checked;
+    this.selection.time = Number(this.memoryUsageSampleSelect.value);
+    this.selection.timeStart = Number(this.timeStartSelect.value);
+    this.selection.timeEnd = Number(this.timeEndSelect.value);
+    this.updatePercentagesInCategory();
+    this.updatePercentagesInZones();
+    this.dispatchEvent(new CustomEvent(
+        'change', {bubbles: true, composed: true, detail: this.selection}));
+  }
+
+  updatePercentagesInCategory() {
+    const overalls = Object.create(null);
+    let overall = 0;
+    // Reset all categories.
+    this.selection.category_names.forEach((_, category) => {
+      overalls[category] = 0;
+    });
+    // Only update categories that have selections.
+    Object.entries(this.selection.categories).forEach(([category, value]) => {
+      overalls[category] =
+          Object.values(value).reduce(
+              (accu, current) => {
+                  const zone_data = this.selectedData.zones.get(current);
+                  return zone_data === undefined ? accu
+                                                 : accu + zone_data.allocated;
+              }, 0) /
+          KB;
+      overall += overalls[category];
+    });
+    Object.entries(overalls).forEach(([category, category_overall]) => {
+      let percents = category_overall / overall * 100;
+      this.$(`#${category}PercentContent`).innerHTML =
+          `${percents.toFixed(1)}%`;
+      this.$('#' + category + 'PercentBackground').style.left = percents + '%';
+    });
+  }
+
+  updatePercentagesInZones() {
+    const selected_data = this.selectedData;
+    const zones_data = selected_data.zones;
+    const total_allocated = selected_data.allocated;
+    this.querySelectorAll('.zonesSelectBox  input').forEach(checkbox => {
+      const zone_name = checkbox.value;
+      const zone_data = zones_data.get(zone_name);
+      const zone_allocated = zone_data === undefined ? 0 : zone_data.allocated;
+      if (zone_allocated == 0) {
+        checkbox.parentNode.style.display = 'none';
+      } else {
+        const percents = zone_allocated / total_allocated;
+        const percent_div = checkbox.parentNode.querySelector('.percentBackground');
+        percent_div.style.left = (percents * 100) + '%';
+        checkbox.parentNode.style.display = 'block';
+      }
+    });
+  }
+
+  selectedInCategory(category) {
+    let tmp = [];
+    this.querySelectorAll('input[name=' + category + 'Checkbox]:checked')
+        .forEach(checkbox => tmp.push(checkbox.value));
+    return tmp;
+  }
+
+  createOption(value, text) {
+    const option = document.createElement('option');
+    option.value = value;
+    option.text = text;
+    return option;
+  }
+
+  populateSelect(id, iterable, labelFn = null, autoselect = null) {
+    if (labelFn == null) labelFn = e => e;
+    let index = 0;
+    for (let [key, value] of iterable) {
+      index++;
+      const label = labelFn(key, value, index);
+      const option = this.createOption(key, label);
+      if (autoselect === key) {
+        option.selected = 'selected';
+      }
+      this.$(id).appendChild(option);
+    }
+  }
+
+  clearCategories() {
+    for (const category of CATEGORIES.keys()) {
+      let f = this.$('#' + category + 'Content');
+      while (f.firstChild) {
+        f.removeChild(f.firstChild);
+      }
+    }
+  }
+
+  populateCategories() {
+    this.clearCategories();
+    const categories = Object.create(null);
+    for (let cat of CATEGORIES.keys()) {
+      categories[cat] = [];
+    }
+
+    for (const [zone_name, zone_stats] of this.selectedIsolate.zones) {
+      const category = categoryByZoneName(zone_name);
+      categories[category].push(zone_name);
+    }
+    for (let category of Object.keys(categories)) {
+      categories[category].sort();
+      for (let zone_name of categories[category]) {
+        this.$('#' + category + 'Content')
+            .appendChild(this.createCheckBox(zone_name, category));
+      }
+    }
+  }
+
+  unselectCategory(category) {
+    this.querySelectorAll('input[name=' + category + 'Checkbox]')
+        .forEach(checkbox => checkbox.checked = false);
+    this.notifySelectionChanged();
+  }
+
+  selectCategory(category) {
+    this.querySelectorAll('input[name=' + category + 'Checkbox]')
+        .forEach(checkbox => checkbox.checked = true);
+    this.notifySelectionChanged();
+  }
+
+  createCheckBox(instance_type, category) {
+    const div = document.createElement('div');
+    div.classList.add('zonesSelectBox');
+    div.style.width = "200px";
+    const input = document.createElement('input');
+    div.appendChild(input);
+    input.type = 'checkbox';
+    input.name = category + 'Checkbox';
+    input.checked = 'checked';
+    input.id = instance_type + 'Checkbox';
+    input.instance_type = instance_type;
+    input.value = instance_type;
+    input.addEventListener('change', e => this.notifySelectionChanged(e));
+    const label = document.createElement('label');
+    div.appendChild(label);
+    label.innerText = instance_type;
+    label.htmlFor = instance_type + 'Checkbox';
+    const percentDiv = document.createElement('div');
+    percentDiv.className = 'percentBackground';
+    div.appendChild(percentDiv);
+    return div;
+  }
+});
diff --git a/chromium/v8/tools/zone-stats/global-timeline-template.html b/chromium/v8/tools/zone-stats/global-timeline-template.html
new file mode 100644
index 00000000000..49e75646f16
--- /dev/null
+++ b/chromium/v8/tools/zone-stats/global-timeline-template.html
@@ -0,0 +1,16 @@
+<!-- Copyright 2020 the V8 project authors. All rights reserved.
+Use of this source code is governed by a BSD-style license that can be
+found in the LICENSE file. -->
+<style>
+#chart {
+  width: 100%;
+  height: 500px;
+}
+</style>
+<div id="container" style="display: none;">
+  <h2>Stats</h2>
+  <p>Peak allocated zone memory <span id="peak-memory-label"></span></p>
+
+  <h2>Timeline</h2>
+  <div id="chart"></div>
+</div>
diff --git a/chromium/v8/tools/zone-stats/global-timeline.js b/chromium/v8/tools/zone-stats/global-timeline.js
new file mode 100644
index 00000000000..ea1793101b4
--- /dev/null
+++ b/chromium/v8/tools/zone-stats/global-timeline.js
@@ -0,0 +1,323 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+'use strict';
+
+import {categoryByZoneName} from './categories.js';
+
+import {
+  VIEW_TOTALS,
+  VIEW_BY_ZONE_NAME,
+  VIEW_BY_ZONE_CATEGORY,
+
+  KIND_ALLOCATED_MEMORY,
+  KIND_USED_MEMORY,
+} from './details-selection.js';
+
+defineCustomElement('global-timeline', (templateText) =>
+ class GlobalTimeline extends HTMLElement {
+  constructor() {
+    super();
+    const shadowRoot = this.attachShadow({mode: 'open'});
+    shadowRoot.innerHTML = templateText;
+  }
+
+  $(id) {
+    return this.shadowRoot.querySelector(id);
+  }
+
+  set data(value) {
+    this._data = value;
+    this.stateChanged();
+  }
+
+  get data() {
+    return this._data;
+  }
+
+  set selection(value) {
+    this._selection = value;
+    this.stateChanged();
+  }
+
+  get selection() {
+    return this._selection;
+  }
+
+  isValid() {
+    return this.data && this.selection;
+  }
+
+  hide() {
+    this.$('#container').style.display = 'none';
+  }
+
+  show() {
+    this.$('#container').style.display = 'block';
+  }
+
+  stateChanged() {
+    if (this.isValid()) {
+      const isolate_data = this.data[this.selection.isolate];
+      const peakAllocatedMemory = isolate_data.peakAllocatedMemory;
+      this.$('#peak-memory-label').innerText = formatBytes(peakAllocatedMemory);
+      this.drawChart();
+    } else {
+      this.hide();
+    }
+  }
+
+  getZoneLabels(zone_names) {
+    switch (this.selection.data_kind) {
+      case KIND_ALLOCATED_MEMORY:
+        return zone_names.map(name => {
+          return {label: name + " (allocated)", type: 'number'};
+        });
+
+      case KIND_USED_MEMORY:
+        return zone_names.map(name => {
+          return {label: name + " (used)", type: 'number'};
+        });
+
+      default:
+        // Don't show detailed per-zone information.
+        return [];
+    }
+  }
+
+  getTotalsData() {
+    const isolate_data = this.data[this.selection.isolate];
+    const labels = [
+      { label: "Time", type: "number" },
+      { label: "Total allocated", type: "number" },
+      { label: "Total used", type: "number" },
+    ];
+    const chart_data = [labels];
+
+    const timeStart = this.selection.timeStart;
+    const timeEnd = this.selection.timeEnd;
+    const filter_entries = timeStart > 0 || timeEnd > 0;
+
+    for (const [time, zone_data] of isolate_data.samples) {
+      if (filter_entries && (time < timeStart || time > timeEnd)) continue;
+      const data = [];
+      data.push(time * kMillis2Seconds);
+      data.push(zone_data.allocated / KB);
+      data.push(zone_data.used / KB);
+      chart_data.push(data);
+    }
+    return chart_data;
+  }
+
+  getZoneData() {
+    const isolate_data = this.data[this.selection.isolate];
+    const zone_names = isolate_data.sorted_zone_names;
+    const selected_zones = this.selection.zones;
+    const data_kind = this.selection.data_kind;
+    const show_totals = this.selection.show_totals;
+    const zones_labels = this.getZoneLabels(zone_names);
+
+    const totals_labels = show_totals
+        ? [
+            { label: "Total allocated", type: "number" },
+            { label: "Total used", type: "number" },
+          ]
+        : [];
+
+    const labels = [
+      { label: "Time", type: "number" },
+      ...totals_labels,
+      ...zones_labels,
+    ];
+    const chart_data = [labels];
+
+    const timeStart = this.selection.timeStart;
+    const timeEnd = this.selection.timeEnd;
+    const filter_entries = timeStart > 0 || timeEnd > 0;
+
+    for (const [time, zone_data] of isolate_data.samples) {
+      if (filter_entries && (time < timeStart || time > timeEnd)) continue;
+      const active_zone_stats = Object.create(null);
+      if (zone_data.zones !== undefined) {
+        for (const [zone_name, zone_stats] of zone_data.zones) {
+          if (!selected_zones.has(zone_name)) continue;  // Not selected, skip.
+
+          const current_stats = active_zone_stats[zone_name];
+          if (current_stats === undefined) {
+            active_zone_stats[zone_name] =
+                { allocated: zone_stats.allocated, used: zone_stats.used };
+          } else {
+            // We've got two zones with the same name.
+            console.log("=== Duplicate zone names: " + zone_name);
+            // Sum stats.
+            current_stats.allocated += zone_stats.allocated;
+            current_stats.used += zone_stats.used;
+          }
+        }
+      }
+
+      const data = [];
+      data.push(time * kMillis2Seconds);
+      if (show_totals) {
+        data.push(zone_data.allocated / KB);
+        data.push(zone_data.used / KB);
+      }
+
+      if (zone_data.used > 30 * MB) {
+        console.log("BOOOM!!!! Zone usage in a sample is too big: " +
+                    (zone_data.used / MB) + " MB");
+      }
+
+      zone_names.forEach(zone => {
+        const sample = active_zone_stats[zone];
+        let used = null;
+        let allocated = null;
+        if (sample !== undefined) {
+          used = sample.used / KB;
+          allocated = sample.allocated / KB;
+        }
+        if (data_kind == KIND_ALLOCATED_MEMORY) {
+          data.push(allocated);
+        } else {
+          // KIND_USED_MEMORY
+          data.push(used);
+        }
+      });
+      chart_data.push(data);
+    }
+    return chart_data;
+  }
+
+  getCategoryData() {
+    const isolate_data = this.data[this.selection.isolate];
+    const categories = Object.keys(this.selection.categories);
+    const categories_names =
+        categories.map(k => this.selection.category_names.get(k));
+    const selected_zones = this.selection.zones;
+    const data_kind = this.selection.data_kind;
+    const show_totals = this.selection.show_totals;
+
+    const categories_labels = this.getZoneLabels(categories_names);
+
+    const totals_labels = show_totals
+        ? [
+            { label: "Total allocated", type: "number" },
+            { label: "Total used", type: "number" },
+          ]
+        : [];
+
+    const labels = [
+      { label: "Time", type: "number" },
+      ...totals_labels,
+      ...categories_labels,
+    ];
+    const chart_data = [labels];
+
+    const timeStart = this.selection.timeStart;
+    const timeEnd = this.selection.timeEnd;
+    const filter_entries = timeStart > 0 || timeEnd > 0;
+
+    for (const [time, zone_data] of isolate_data.samples) {
+      if (filter_entries && (time < timeStart || time > timeEnd)) continue;
+      const active_category_stats = Object.create(null);
+      if (zone_data.zones !== undefined) {
+        for (const [zone_name, zone_stats] of zone_data.zones) {
+          const category = selected_zones.get(zone_name);
+          if (category === undefined) continue;  // Zone was not selected.
+
+          const current_stats = active_category_stats[category];
+          if (current_stats === undefined) {
+            active_category_stats[category] =
+                { allocated: zone_stats.allocated, used: zone_stats.used };
+          } else {
+            // Sum stats.
+            current_stats.allocated += zone_stats.allocated;
+            current_stats.used += zone_stats.used;
+          }
+        }
+      }
+
+      const data = [];
+      data.push(time * kMillis2Seconds);
+      if (show_totals) {
+        data.push(zone_data.allocated / KB);
+        data.push(zone_data.used / KB);
+      }
+
+      categories.forEach(category => {
+        const sample = active_category_stats[category];
+        let used = null;
+        let allocated = null;
+        if (sample !== undefined) {
+          used = sample.used / KB;
+          allocated = sample.allocated / KB;
+        }
+        if (data_kind == KIND_ALLOCATED_MEMORY) {
+          data.push(allocated);
+        } else {
+          // KIND_USED_MEMORY
+          data.push(used);
+        }
+      });
+      chart_data.push(data);
+    }
+    return chart_data;
+  }
+
+  getChartData() {
+    switch (this.selection.data_view) {
+      case VIEW_BY_ZONE_NAME:
+        return this.getZoneData();
+      case VIEW_BY_ZONE_CATEGORY:
+        return this.getCategoryData();
+      case VIEW_TOTALS:
+      default:
+        return this.getTotalsData();
+      }
+  }
+
+  getChartOptions() {
+    const options = {
+      isStacked: true,
+      interpolateNulls: true,
+      hAxis: {
+        format: '###.##s',
+        title: 'Time [s]',
+      },
+      vAxis: {
+        format: '#,###KB',
+        title: 'Memory consumption [KBytes]'
+      },
+      chartArea: {left:100, width: '85%', height: '70%'},
+      legend: {position: 'top', maxLines: '1'},
+      pointsVisible: true,
+      pointSize: 3,
+      explorer: {},
+    };
+
+    // Overlay total allocated/used points on top of the graph.
+    const series = {}
+    if (this.selection.data_view == VIEW_TOTALS) {
+      series[0] = {type: 'line', color: "red"};
+      series[1] = {type: 'line', color: "blue"};
+    } else if (this.selection.show_totals) {
+      series[0] = {type: 'line', color: "red", lineDashStyle: [13, 13]};
+      series[1] = {type: 'line', color: "blue", lineDashStyle: [13, 13]};
+    }
+    return Object.assign(options, {series: series});
+  }
+
+  drawChart() {
+    console.assert(this.data, 'invalid data');
+    console.assert(this.selection, 'invalid selection');
+
+    const chart_data = this.getChartData();
+
+    const data = google.visualization.arrayToDataTable(chart_data);
+    const options = this.getChartOptions();
+    const chart = new google.visualization.AreaChart(this.$('#chart'));
+    this.show();
+    chart.draw(data, google.charts.Line.convertOptions(options));
+  }
+});
diff --git a/chromium/v8/tools/zone-stats/helper.js b/chromium/v8/tools/zone-stats/helper.js
new file mode 100644
index 00000000000..a0d04859d1c
--- /dev/null
+++ b/chromium/v8/tools/zone-stats/helper.js
@@ -0,0 +1,30 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+const KB = 1024;
+const MB = KB * KB;
+const GB = MB * KB;
+const kMillis2Seconds = 1 / 1000;
+
+function formatBytes(bytes) {
+  const units = [' B', ' KB', ' MB', ' GB'];
+  const divisor = 1024;
+  let index = 0;
+  while (index < units.length && bytes >= divisor) {
+    index++;
+    bytes /= divisor;
+  }
+  return bytes.toFixed(2) + units[index];
+}
+
+function formatSeconds(millis) {
+  return (millis * kMillis2Seconds).toFixed(2) + 's';
+}
+
+function defineCustomElement(name, generator) {
+  let htmlTemplatePath = name + '-template.html';
+  fetch(htmlTemplatePath)
+    .then(stream => stream.text())
+    .then(templateText => customElements.define(name, generator(templateText)));
+}
diff --git a/chromium/v8/tools/zone-stats/index.html b/chromium/v8/tools/zone-stats/index.html
new file mode 100644
index 00000000000..5997aab8831
--- /dev/null
+++ b/chromium/v8/tools/zone-stats/index.html
@@ -0,0 +1,93 @@
+<!DOCTYPE html>
+<!-- Copyright 2020 the V8 project authors. All rights reserved.
+Use of this source code is governed by a BSD-style license that can be
+found in the LICENSE file. -->
+
+<html lang="en">
+
+<head>
+  <meta charset="UTF-8">
+  <title>V8 Heap Statistics</title>
+  <link href='https://fonts.googleapis.com/css?family=Roboto' rel='stylesheet'>
+  <script
+          src="https://www.gstatic.com/charts/loader.js"></script>
+  <script
+          src="https://cdnjs.cloudflare.com/ajax/libs/pako/1.0.6/pako_inflate.js"
+          integrity1="sha256-N1z6ddQzX83fjw8v7uSNe7/MgOmMKdwFUv1+AJMDqNM="
+          crossorigin="anonymous"></script>
+
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/oboe.js/2.1.5/oboe-browser.js"
+          crossorigin="anonymous"></script>
+  <script src="helper.js"></script>
+
+  <script type="module" src="details-selection.js"></script>
+  <script type="module" src="global-timeline.js"></script>
+  <script type="module" src="trace-file-reader.js"></script>
+
+  <style>
+body {
+  font-family: 'Roboto', sans-serif;
+  margin-left: 5%;
+  margin-right: 5%;
+}
+
+  </style>
+  <script>
+'use strict';
+
+google.charts.load('current', {'packages':['line', 'corechart', 'bar']});
+
+function $(id) { return document.querySelector(id); }
+
+function removeAllChildren(node) {
+  while (node.firstChild) {
+    node.removeChild(node.firstChild);
+  }
+}
+
+let state = Object.create(null);
+
+function globalDataChanged(e) {
+  state.data = e.detail;
+  // Emit one entry with the whole model for debugging purposes.
+  console.log(state.data);
+  state.selection = null;
+  $('#global-timeline').selection = state.selection;
+  $('#global-timeline').data = state.data;
+  $('#details-selection').data = state.data;
+}
+
+function globalSelectionChangedA(e) {
+  state.selection = e.detail;
+  console.log(state.selection);
+  $('#global-timeline').selection = state.selection;
+}
+
+  </script>
+</head>
+
+<body>
+  <h1>V8 Zone memory usage Statistics</h1>
+  <trace-file-reader onchange="globalDataChanged(event)"></trace-file-reader>
+
+  <details-selection id="details-selection" onchange="globalSelectionChangedA(event)"></details-selection>
+  <global-timeline id="global-timeline"></global-timeline>
+
+  <p>Visualize zone usage profile and statistics that have been gathered using</p>
+  <ul>
+    <li><code>--trace-zone-stats</code> on V8</li>
+    <li>
+      <a
+        href="https://www.chromium.org/developers/how-tos/trace-event-profiling-tool">Chrome's
+        tracing infrastructure</a> collecting data for the category
+      <code>v8.zone_stats</code>.
+    </li>
+  </ul>
+  <p>
+    Note that the visualizer needs to run on a web server due to HTML imports
+    requiring <a
+         href="https://en.wikipedia.org/wiki/Cross-origin_resource_sharing">CORS</a>.
+  </p>
+</body>
+
+</html>
diff --git a/chromium/v8/tools/zone-stats/model.js b/chromium/v8/tools/zone-stats/model.js
new file mode 100644
index 00000000000..80f45237631
--- /dev/null
+++ b/chromium/v8/tools/zone-stats/model.js
@@ -0,0 +1,92 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+'use strict';
+
+export class Isolate {
+  constructor(address) {
+    this.address = address;
+    this.start = null;
+    this.end = null;
+    this.peakUsageTime = null;
+    // Maps zone name to per-zone statistics.
+    this.zones = new Map();
+    // Zone names sorted by memory usage (from low to high).
+    this.sorted_zone_names = [];
+    // Maps time to total and per-zone memory usages.
+    this.samples = new Map();
+
+    this.peakAllocatedMemory = 0;
+
+    // Maps zone name to their max memory consumption.
+    this.zonePeakMemory = Object.create(null);
+    // Peak memory consumed by a single zone.
+    this.singleZonePeakMemory = 0;
+  }
+
+  finalize() {
+    this.samples.forEach(sample => this.finalizeSample(sample));
+    this.start = Math.floor(this.start);
+    this.end = Math.ceil(this.end);
+    this.sortZoneNamesByPeakMemory();
+  }
+
+  getLabel() {
+    let label = `${this.address}: `;
+    label += ` peak=${formatBytes(this.peakAllocatedMemory)}`;
+    label += ` time=[${this.start}, ${this.end}] ms`;
+    return label;
+  }
+
+  finalizeSample(sample) {
+    const time = sample.time;
+    if (this.start == null) {
+      this.start = time;
+      this.end = time;
+    } else {
+      this.end = Math.max(this.end, time);
+    }
+
+    const allocated = sample.allocated;
+    if (allocated > this.peakAllocatedMemory) {
+      this.peakUsageTime = time;
+      this.peakAllocatedMemory = allocated;
+    }
+
+    const sample_zones = sample.zones;
+    if (sample_zones !== undefined) {
+      sample.zones.forEach((zone_sample, zone_name) => {
+        let zone_stats = this.zones.get(zone_name);
+        if (zone_stats === undefined) {
+          zone_stats = {max_allocated: 0, max_used: 0};
+          this.zones.set(zone_name, zone_stats);
+        }
+
+        zone_stats.max_allocated =
+            Math.max(zone_stats.max_allocated, zone_sample.allocated);
+        zone_stats.max_used = Math.max(zone_stats.max_used, zone_sample.used);
+      });
+    }
+  }
+
+  sortZoneNamesByPeakMemory() {
+    let entries = [...this.zones.keys()];
+    entries.sort((a, b) =>
+      this.zones.get(a).max_allocated - this.zones.get(b).max_allocated
+    );
+    this.sorted_zone_names = entries;
+
+    let max = 0;
+    for (let [key, value] of entries) {
+      this.zonePeakMemory[key] = value;
+      max = Math.max(max, value);
+    }
+    this.singleZonePeakMemory = max;
+  }
+
+  getInstanceTypePeakMemory(type) {
+    if (!(type in this.zonePeakMemory)) return 0;
+    return this.zonePeakMemory[type];
+  }
+}
diff --git a/chromium/v8/tools/zone-stats/trace-file-reader-template.html b/chromium/v8/tools/zone-stats/trace-file-reader-template.html
new file mode 100644
index 00000000000..ede7ee9a75b
--- /dev/null
+++ b/chromium/v8/tools/zone-stats/trace-file-reader-template.html
@@ -0,0 +1,81 @@
+<!-- Copyright 2020 the V8 project authors. All rights reserved.
+Use of this source code is governed by a BSD-style license that can be
+found in the LICENSE file. -->
+<style>
+#fileReader {
+  width: 100%;
+  height: 100px;
+  line-height: 100px;
+  text-align: center;
+  border: solid 1px #000000;
+  border-radius: 5px;
+  cursor: pointer;
+  transition: all 0.5s ease-in-out;
+}
+
+#fileReader.done {
+    height: 20px;
+    line-height: 20px;
+}
+
+#fileReader:hover {
+  background-color: #e0edfe ;
+}
+
+.loading #fileReader {
+  cursor: wait;
+}
+
+#fileReader > input {
+  display: none;
+}
+
+
+#loader {
+  display: none;
+}
+
+.loading #loader {
+  display: block;
+  position: fixed;
+  top: 0px;
+  left: 0px;
+  width: 100%;
+  height: 100%;
+  background-color: rgba(255, 255, 255, 0.5);
+}
+
+#spinner {
+  position: absolute;
+  width: 100px;
+  height: 100px;
+  top: 40%;
+  left: 50%;
+  margin-left: -50px;
+  border: 30px solid #000;
+  border-top: 30px solid #36E;
+  border-radius: 50%;
+  animation: spin 1s ease-in-out infinite;
+}
+
+@keyframes spin {
+ 0% {
+    transform: rotate(0deg);
+ }
+ 100% {
+    transform: rotate(360deg);
+ }
+}
+</style>
+
+<section id="fileReaderSection">
+  <div id="fileReader" tabindex=1 >
+    <span id="label">
+      Drag and drop a trace file into this area, or click to choose from disk.
+     </span>
+    <input id="file" type="file" name="file" />
+  </div>
+  <div id="loader">
+    <div id="spinner"></div>
+  </div>
+</section>
diff --git a/chromium/v8/tools/zone-stats/trace-file-reader.js b/chromium/v8/tools/zone-stats/trace-file-reader.js
new file mode 100644
index 00000000000..6decfa8f273
--- /dev/null
+++ b/chromium/v8/tools/zone-stats/trace-file-reader.js
@@ -0,0 +1,294 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+'use strict';
+
+import {Isolate} from './model.js';
+
+defineCustomElement('trace-file-reader', (templateText) =>
+ class TraceFileReader extends HTMLElement {
+  constructor() {
+    super();
+    const shadowRoot = this.attachShadow({mode: 'open'});
+    shadowRoot.innerHTML = templateText;
+    this.addEventListener('click', e => this.handleClick(e));
+    this.addEventListener('dragover', e => this.handleDragOver(e));
+    this.addEventListener('drop', e => this.handleChange(e));
+    this.$('#file').addEventListener('change', e => this.handleChange(e));
+    this.$('#fileReader').addEventListener('keydown', e => this.handleKeyEvent(e));
+  }
+
+  $(id) {
+    return this.shadowRoot.querySelector(id);
+  }
+
+  get section() {
+    return this.$('#fileReaderSection');
+  }
+
+  updateLabel(text) {
+    this.$('#label').innerText = text;
+  }
+
+  handleKeyEvent(event) {
+    if (event.key == "Enter") this.handleClick(event);
+  }
+
+  handleClick(event) {
+    this.$('#file').click();
+  }
+
+  handleChange(event) {
+    // Used for drop and file change.
+    event.preventDefault();
+    var host = event.dataTransfer ? event.dataTransfer : event.target;
+    this.readFile(host.files[0]);
+  }
+
+  handleDragOver(event) {
+    event.preventDefault();
+  }
+
+  connectedCallback() {
+    this.$('#fileReader').focus();
+  }
+
+  readFile(file) {
+    if (!file) {
+      this.updateLabel('Failed to load file.');
+      return;
+    }
+    this.$('#fileReader').blur();
+
+    this.section.className = 'loading';
+    const reader = new FileReader();
+
+    if (['application/gzip', 'application/x-gzip'].includes(file.type)) {
+      reader.onload = (e) => {
+        try {
+          // Decode data as strings of 64Kb chunks. Bigger chunks may cause
+          // parsing failures in Oboe.js.
+          const chunkedInflate = new pako.Inflate(
+            {to: 'string', chunkSize: 65536}
+          );
+          let processingState = undefined;
+          chunkedInflate.onData = (chunk) => {
+            if (processingState === undefined) {
+              processingState = this.startProcessing(file, chunk);
+            } else {
+              processingState.processChunk(chunk);
+            }
+          };
+          chunkedInflate.onEnd = () => {
+            if (processingState !== undefined) {
+              const result_data = processingState.endProcessing();
+              this.processLoadedData(file, result_data);
+            }
+          };
+          console.log("======");
+          const textResult = chunkedInflate.push(e.target.result);
+
+          this.section.className = 'success';
+          this.$('#fileReader').classList.add('done');
+        } catch (err) {
+          console.error(err);
+          this.section.className = 'failure';
+        }
+      };
+      // Delay the loading a bit to allow for CSS animations to happen.
+      setTimeout(() => reader.readAsArrayBuffer(file), 0);
+    } else {
+      reader.onload = (e) => {
+        try {
+          // Process the whole file in at once.
+          const processingState = this.startProcessing(file, e.target.result);
+          const dataModel = processingState.endProcessing();
+          this.processLoadedData(file, dataModel);
+
+          this.section.className = 'success';
+          this.$('#fileReader').classList.add('done');
+        } catch (err) {
+          console.error(err);
+          this.section.className = 'failure';
+        }
+      };
+      // Delay the loading a bit to allow for CSS animations to happen.
+      setTimeout(() => reader.readAsText(file), 0);
+    }
+  }
+
+  processLoadedData(file, dataModel) {
+    console.log("Trace file parsed successfully.");
+    this.extendAndSanitizeModel(dataModel);
+    this.updateLabel('Finished loading \'' + file.name + '\'.');
+    this.dispatchEvent(new CustomEvent(
+        'change', {bubbles: true, composed: true, detail: dataModel}));
+  }
+
+  createOrUpdateEntryIfNeeded(data, entry) {
+    console.assert(entry.isolate, 'entry should have an isolate');
+    if (!(entry.isolate in data)) {
+      data[entry.isolate] = new Isolate(entry.isolate);
+    }
+  }
+
+  extendAndSanitizeModel(data) {
+    const checkNonNegativeProperty = (obj, property) => {
+      console.assert(obj[property] >= 0, 'negative property', obj, property);
+    };
+
+    Object.values(data).forEach(isolate => isolate.finalize());
+  }
+
+  processOneZoneStatsEntry(data, entry_stats) {
+    this.createOrUpdateEntryIfNeeded(data, entry_stats);
+    const isolate_data = data[entry_stats.isolate];
+    let zones = undefined;
+    const entry_zones = entry_stats.zones;
+    if (entry_zones !== undefined) {
+      zones = new Map();
+      entry_zones.forEach(zone => {
+        // There might be multiple occurrences of the same zone in the set,
+        // combine numbers in this case.
+        const existing_zone_stats = zones.get(zone.name);
+        if (existing_zone_stats !== undefined) {
+          existing_zone_stats.allocated += zone.allocated;
+          existing_zone_stats.used += zone.used;
+        } else {
+          zones.set(zone.name, {allocated: zone.allocated, used: zone.used});
+        }
+      });
+    }
+    const time = entry_stats.time;
+    const sample = {
+      time: time,
+      allocated: entry_stats.allocated,
+      used: entry_stats.used,
+      zones: zones
+    };
+    isolate_data.samples.set(time, sample);
+  }
+
+  startProcessing(file, chunk) {
+    const isV8TraceFile = chunk.includes('v8-zone-trace');
+    const processingState =
+        isV8TraceFile ? this.startProcessingAsV8TraceFile(file)
+                      : this.startProcessingAsChromeTraceFile(file);
+
+    processingState.processChunk(chunk);
+    return processingState;
+  }
+
+  startProcessingAsChromeTraceFile(file) {
+    console.log(`Processing log as chrome trace file.`);
+    const data = Object.create(null);  // Final data container.
+    const parseOneZoneEvent = (actual_data) => {
+      if ('stats' in actual_data) {
+        try {
+          const entry_stats = JSON.parse(actual_data.stats);
+          this.processOneZoneStatsEntry(data, entry_stats);
+        } catch (e) {
+          console.error('Unable to parse data set entry', e);
+        }
+      }
+    };
+    const zone_events_filter = (event) => {
+      if (event.name == 'V8.Zone_Stats') {
+        parseOneZoneEvent(event.args);
+      }
+      return oboe.drop;
+    };
+
+    const oboe_stream = oboe();
+    // Trace files support two formats.
+    oboe_stream
+        // 1) {traceEvents: [ data ]}
+        .node('traceEvents.*', zone_events_filter)
+        // 2) [ data ]
+        .node('!.*', zone_events_filter)
+        .fail((errorReport) => {
+          throw new Error("Trace data parse failed: " + errorReport.thrown);
+        });
+
+    let failed = false;
+
+    const processingState = {
+      file: file,
+
+      processChunk(chunk) {
+        if (failed) return false;
+        try {
+          oboe_stream.emit('data', chunk);
+          return true;
+        } catch (e) {
+          console.error('Unable to parse chrome trace file.', e);
+          failed = true;
+          return false;
+        }
+      },
+
+      endProcessing() {
+        if (failed) return null;
+        oboe_stream.emit('end');
+        return data;
+      },
+    };
+    return processingState;
+  }
+
+  startProcessingAsV8TraceFile(file) {
+    console.log('Processing log as V8 trace file.');
+    const data = Object.create(null);  // Final data container.
+
+    const processOneLine = (line) => {
+      try {
+        // Strip away a potentially present adb logcat prefix.
+        line = line.replace(/^I\/v8\s*\(\d+\):\s+/g, '');
+
+        const entry = JSON.parse(line);
+        if (entry === null || entry.type === undefined) return;
+        if ((entry.type === 'v8-zone-trace') && ('stats' in entry)) {
+          const entry_stats = entry.stats;
+          this.processOneZoneStatsEntry(data, entry_stats);
+        } else {
+          console.log('Unknown entry type: ' + entry.type);
+        }
+      } catch (e) {
+        console.log('Unable to parse line: \'' + line + '\' (' + e + ')');
+      }
+    };
+
+    let prev_chunk_leftover = "";
+
+    const processingState = {
+      file: file,
+
+      processChunk(chunk) {
+        const contents = chunk.split('\n');
+        const last_line = contents.pop();
+        const linesCount = contents.length;
+        if (linesCount == 0) {
+          // There was only one line in the chunk, it may still be unfinished.
+          prev_chunk_leftover += last_line;
+        } else {
+          contents[0] = prev_chunk_leftover + contents[0];
+          prev_chunk_leftover = last_line;
+          for (let line of contents) {
+            processOneLine(line);
+          }
+        }
+        return true;
+      },
+
+      endProcessing() {
+        if (prev_chunk_leftover.length > 0) {
+          processOneLine(prev_chunk_leftover);
+          prev_chunk_leftover = "";
+        }
+        return data;
+      },
+    };
+    return processingState;
+  }
+});