1 files changed, 7 insertions, 23 deletions
diff --git a/deps/v8/src/strings/string-builder-inl.h b/deps/v8/src/strings/string-builder-inl.h
index b6ee62ce0a..0170415833 100644
--- a/deps/v8/src/strings/string-builder-inl.h
+++ b/deps/v8/src/strings/string-builder-inl.h
@@ -39,6 +39,10 @@ class FixedArrayBuilder {
   explicit FixedArrayBuilder(Isolate* isolate, int initial_capacity);
   explicit FixedArrayBuilder(Handle<FixedArray> backing_store);
 
+  // Creates a FixedArrayBuilder which allocates its backing store lazily when
+  // EnsureCapacity is called.
+  static FixedArrayBuilder Lazy(Isolate* isolate);
+
   bool HasCapacity(int elements);
   void EnsureCapacity(Isolate* isolate, int elements);
 
@@ -51,9 +55,9 @@ class FixedArrayBuilder {
 
   int capacity();
 
-  Handle<JSArray> ToJSArray(Handle<JSArray> target_array);
-
  private:
+  explicit FixedArrayBuilder(Isolate* isolate);
+
   Handle<FixedArray> array_;
   int length_;
   bool has_non_smi_elements_;
@@ -257,26 +261,6 @@ class IncrementalStringBuilder {
   };
 
   template <typename DestChar>
-  class NoExtendString : public NoExtend<DestChar> {
-   public:
-    NoExtendString(Handle<String> string, int required_length)
-        : NoExtend<DestChar>(string, 0), string_(string) {
-      DCHECK(string->length() >= required_length);
-    }
-
-    Handle<String> Finalize() {
-      Handle<SeqString> string = Handle<SeqString>::cast(string_);
-      int length = NoExtend<DestChar>::written();
-      Handle<String> result = SeqString::Truncate(string, length);
-      string_ = Handle<String>();
-      return result;
-    }
-
-   private:
-    Handle<String> string_;
-  };
-
-  template <typename DestChar>
   class NoExtendBuilder : public NoExtend<DestChar> {
    public:
     NoExtendBuilder(IncrementalStringBuilder* builder, int required_length,
@@ -325,7 +309,7 @@ class IncrementalStringBuilder {
   void ShrinkCurrentPart() {
     DCHECK(current_index_ < part_length_);
     set_current_part(SeqString::Truncate(
-        Handle<SeqString>::cast(current_part()), current_index_));
+        isolate_, Handle<SeqString>::cast(current_part()), current_index_));
   }
 
   void AppendStringByCopy(Handle<String> string);