Imported QtWebKit TP3 (git b57bc6801f1876c3220d5a4bfea33d620d477443)

Change-Id: I3b1d8a2808782c9f34d50240000e20cb38d3680f
Reviewed-by: Konstantin Tokarev <annulen@yandex.ru>

1 files changed, 1271 insertions, 1407 deletions

diff --git a/Source/WebCore/page/EventHandler.cpp b/Source/WebCore/page/EventHandler.cpp
index fd9bb59aa..f13749ba0 100644
--- a/Source/WebCore/page/EventHandler.cpp
+++ b/Source/WebCore/page/EventHandler.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2006-2016 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2015 The Qt Company Ltd
  *
@@ -12,10 +12,10 @@
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
- * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
@@ -30,6 +30,7 @@
 
 #include "AXObjectCache.h"
 #include "AutoscrollController.h"
+#include "BackForwardController.h"
 #include "CachedImage.h"
 #include "Chrome.h"
 #include "ChromeClient.h"
@@ -42,12 +43,11 @@
 #include "Editor.h"
 #include "EditorClient.h"
 #include "EventNames.h"
-#include "EventPathWalker.h"
 #include "ExceptionCodePlaceholder.h"
+#include "FileList.h"
 #include "FloatPoint.h"
 #include "FloatRect.h"
 #include "FocusController.h"
-#include "Frame.h"
 #include "FrameLoader.h"
 #include "FrameSelection.h"
 #include "FrameTree.h"
@@ -62,19 +62,26 @@
 #include "Image.h"
 #include "InspectorInstrumentation.h"
 #include "KeyboardEvent.h"
+#include "MainFrame.h"
 #include "MouseEvent.h"
 #include "MouseEventWithHitTestResults.h"
 #include "Page.h"
+#include "PageOverlayController.h"
 #include "PlatformEvent.h"
 #include "PlatformKeyboardEvent.h"
 #include "PlatformWheelEvent.h"
 #include "PluginDocument.h"
 #include "RenderFrameSet.h"
 #include "RenderLayer.h"
+#include "RenderListBox.h"
+#include "RenderNamedFlowThread.h"
 #include "RenderTextControlSingleLine.h"
 #include "RenderView.h"
 #include "RenderWidget.h"
-#include "ScrollAnimator.h"
+#include "RuntimeApplicationChecks.h"
+#include "SVGDocument.h"
+#include "SVGNames.h"
+#include "ScrollLatchingState.h"
 #include "Scrollbar.h"
 #include "Settings.h"
 #include "ShadowRoot.h"
@@ -84,36 +91,35 @@
 #include "TextIterator.h"
 #include "UserGestureIndicator.h"
 #include "UserTypingGestureIndicator.h"
+#include "VisibleUnits.h"
 #include "WheelEvent.h"
 #include "WindowsKeyboardCodes.h"
 #include <wtf/Assertions.h>
 #include <wtf/CurrentTime.h>
+#include <wtf/NeverDestroyed.h>
 #include <wtf/StdLibExtras.h>
 #include <wtf/TemporaryChange.h>
+#include <wtf/WeakPtr.h>
 
-#if ENABLE(GESTURE_EVENTS)
-#include "PlatformGestureEvent.h"
-#endif
-
-#if ENABLE(TOUCH_ADJUSTMENT)
-#include "TouchAdjustment.h"
+#if ENABLE(CSS_IMAGE_SET)
+#include "StyleCachedImageSet.h"
 #endif
 
-#if ENABLE(SVG)
-#include "SVGDocument.h"
-#include "SVGElementInstance.h"
-#include "SVGNames.h"
-#include "SVGUseElement.h"
+#if ENABLE(IOS_TOUCH_EVENTS)
+#include "PlatformTouchEventIOS.h"
 #endif
 
 #if ENABLE(TOUCH_EVENTS)
-#include "PlatformTouchEvent.h"
 #include "TouchEvent.h"
 #include "TouchList.h"
 #endif
 
-#if ENABLE(CSS_IMAGE_SET)
-#include "StyleCachedImageSet.h"
+#if ENABLE(TOUCH_EVENTS) && !ENABLE(IOS_TOUCH_EVENTS)
+#include "PlatformTouchEvent.h"
+#endif
+
+#if ENABLE(MAC_GESTURE_EVENTS)
+#include "PlatformGestureEventMac.h"
 #endif
 
 namespace WebCore {
@@ -130,25 +136,38 @@ const int TextDragHysteresis = 3;
 const int GeneralDragHysteresis = 3;
 #endif // ENABLE(DRAG_SUPPORT)
 
+#if ENABLE(IOS_GESTURE_EVENTS) || ENABLE(MAC_GESTURE_EVENTS)
+const float GestureUnknown = 0;
+#endif
+
+#if ENABLE(IOS_TOUCH_EVENTS)
+// FIXME: Share this constant with EventHandler and SliderThumbElement.
+const unsigned InvalidTouchIdentifier = 0;
+#endif
+
 // Match key code of composition keydown event on windows.
 // IE sends VK_PROCESSKEY which has value 229;
 const int CompositionEventKeyCode = 229;
 
-#if ENABLE(SVG)
 using namespace SVGNames;
-#endif
 
+#if !ENABLE(IOS_TOUCH_EVENTS)
 // The amount of time to wait before sending a fake mouse event, triggered
-// during a scroll. The short interval is used if the content responds to the mouse events quickly enough,
-// otherwise the long interval is used.
+// during a scroll. The short interval is used if the content responds to the mouse events
+// in fakeMouseMoveDurationThreshold or less, otherwise the long interval is used.
+const double fakeMouseMoveDurationThreshold = 0.01;
 const double fakeMouseMoveShortInterval = 0.1;
-const double fakeMouseMoveLongInterval = 0.250;
+const double fakeMouseMoveLongInterval = 0.25;
+#endif
 
+#if ENABLE(CURSOR_SUPPORT)
 // The amount of time to wait for a cursor update on style and layout changes
 // Set to 50Hz, no need to be faster than common screen refresh rate
 const double cursorUpdateInterval = 0.02;
 
 const int maximumCursorSize = 128;
+#endif
+
 #if ENABLE(MOUSE_CURSOR_SCALE)
 // It's pretty unlikely that a scale of less than one would ever be used. But all we really
 // need to ensure here is that the scale isn't so small that integer overflow can occur when
@@ -181,7 +200,7 @@ public:
 
     ~MaximumDurationTracker()
     {
-        *m_maxDuration = max(*m_maxDuration, monotonicallyIncreasingTime() - m_start);
+        *m_maxDuration = std::max(*m_maxDuration, monotonicallyIncreasingTime() - m_start);
     }
 
 private:
@@ -189,7 +208,7 @@ private:
     double m_start;
 };
 
-#if ENABLE(TOUCH_EVENTS)
+#if ENABLE(TOUCH_EVENTS) && !ENABLE(IOS_TOUCH_EVENTS)
 class SyntheticTouchPoint : public PlatformTouchPoint {
 public:
 
@@ -254,7 +273,7 @@ public:
         m_touchPoints.append(SyntheticTouchPoint(event));
     }
 };
-#endif
+#endif // ENABLE(TOUCH_EVENTS) && !ENABLE(IOS_TOUCH_EVENTS)
 
 static inline ScrollGranularity wheelGranularityToScrollGranularity(unsigned deltaMode)
 {
@@ -270,17 +289,65 @@ static inline ScrollGranularity wheelGranularityToScrollGranularity(unsigned del
     }
 }
 
-static inline bool scrollNode(float delta, ScrollGranularity granularity, ScrollDirection positiveDirection, ScrollDirection negativeDirection, Node* node, Node** stopNode)
+static inline bool didScrollInScrollableArea(ScrollableArea* scrollableArea, WheelEvent* wheelEvent)
 {
-    if (!delta)
-        return false;
-    if (!node->renderer())
+    ScrollGranularity scrollGranularity = wheelGranularityToScrollGranularity(wheelEvent->deltaMode());
+    bool didHandleWheelEvent = false;
+    if (float absoluteDelta = std::abs(wheelEvent->deltaX()))
+        didHandleWheelEvent |= scrollableArea->scroll(wheelEvent->deltaX() > 0 ? ScrollRight : ScrollLeft, scrollGranularity, absoluteDelta);
+    
+    if (float absoluteDelta = std::abs(wheelEvent->deltaY()))
+        didHandleWheelEvent |= scrollableArea->scroll(wheelEvent->deltaY() > 0 ? ScrollDown : ScrollUp, scrollGranularity, absoluteDelta);
+    
+    return didHandleWheelEvent;
+}
+
+static inline bool handleWheelEventInAppropriateEnclosingBox(Node* startNode, WheelEvent* wheelEvent, Element** stopElement, const FloatSize& filteredPlatformDelta)
+{
+    bool shouldHandleEvent = wheelEvent->deltaX() || wheelEvent->deltaY();
+#if PLATFORM(MAC)
+    shouldHandleEvent |= wheelEvent->phase() == PlatformWheelEventPhaseEnded;
+#if ENABLE(CSS_SCROLL_SNAP)
+    shouldHandleEvent |= wheelEvent->momentumPhase() == PlatformWheelEventPhaseEnded;
+#endif
+#endif
+    if (!startNode->renderer() || !shouldHandleEvent)
         return false;
-    RenderBox* enclosingBox = node->renderer()->enclosingBox();
-    float absDelta = delta > 0 ? delta : -delta;
-    return enclosingBox->scroll(delta < 0 ? negativeDirection : positiveDirection, granularity, absDelta, stopNode);
+
+    RenderBox& initialEnclosingBox = startNode->renderer()->enclosingBox();
+    if (initialEnclosingBox.isListBox())
+        return didScrollInScrollableArea(static_cast<RenderListBox*>(&initialEnclosingBox), wheelEvent);
+
+    RenderBox* currentEnclosingBox = &initialEnclosingBox;
+    while (currentEnclosingBox) {
+        if (RenderLayer* boxLayer = currentEnclosingBox->layer()) {
+            const PlatformWheelEvent* platformEvent = wheelEvent->wheelEvent();
+            bool scrollingWasHandled;
+            if (platformEvent != nullptr)
+                scrollingWasHandled = boxLayer->handleWheelEvent(platformEvent->copyWithDeltas(filteredPlatformDelta.width(), filteredPlatformDelta.height()));
+            else
+                scrollingWasHandled = didScrollInScrollableArea(boxLayer, wheelEvent);
+
+            if (scrollingWasHandled) {
+                if (stopElement)
+                    *stopElement = currentEnclosingBox->element();
+                return true;
+            }
+        }
+
+        if (stopElement && *stopElement && *stopElement == currentEnclosingBox->element())
+            return true;
+
+        currentEnclosingBox = currentEnclosingBox->containingBlock();
+        if (currentEnclosingBox && currentEnclosingBox->isRenderNamedFlowThread())
+            currentEnclosingBox = RenderNamedFlowThread::fragmentFromRenderBoxAsRenderBlock(currentEnclosingBox, roundedIntPoint(wheelEvent->absoluteLocation()), initialEnclosingBox);
+        if (!currentEnclosingBox || currentEnclosingBox->isRenderView())
+            return false;
+    }
+    return false;
 }
 
+#if (ENABLE(TOUCH_EVENTS) && !PLATFORM(IOS))
 static inline bool shouldGesturesTriggerActive()
 {
     // If the platform we're on supports GestureTapDown and GestureTapCancel then we'll
@@ -288,8 +355,9 @@ static inline bool shouldGesturesTriggerActive()
     // know in advance what event types are supported.
     return false;
 }
+#endif
 
-#if !PLATFORM(MAC)
+#if !PLATFORM(COCOA)
 
 inline bool EventHandler::eventLoopHandleMouseUp(const MouseEventWithHitTestResults&)
 {
@@ -305,59 +373,27 @@ inline bool EventHandler::eventLoopHandleMouseDragged(const MouseEventWithHitTes
 
 #endif
 
-EventHandler::EventHandler(Frame* frame)
+EventHandler::EventHandler(Frame& frame)
     : m_frame(frame)
-    , m_mousePressed(false)
-    , m_capturesDragging(false)
-    , m_mouseDownMayStartSelect(false)
-#if ENABLE(DRAG_SUPPORT)
-    , m_mouseDownMayStartDrag(false)
-    , m_dragMayStartSelectionInstead(false)
-#endif
-    , m_mouseDownWasSingleClickInSelection(false)
-    , m_selectionInitiationState(HaveNotStartedSelection)
-    , m_hoverTimer(this, &EventHandler::hoverTimerFired)
-    , m_cursorUpdateTimer(this, &EventHandler::cursorUpdateTimerFired)
-    , m_autoscrollController(adoptPtr(new AutoscrollController))
-    , m_mouseDownMayStartAutoscroll(false)
-    , m_mouseDownWasInSubframe(false)
-    , m_fakeMouseMoveEventTimer(this, &EventHandler::fakeMouseMoveEventTimerFired)
-#if ENABLE(SVG)
-    , m_svgPan(false)
-#endif
-    , m_resizeLayer(0)
-    , m_eventHandlerWillResetCapturingMouseEventsNode(0)
-    , m_clickCount(0)
-    , m_mousePositionIsUnknown(true)
-    , m_mouseDownTimestamp(0)
-    , m_widgetIsLatched(false)
-#if PLATFORM(MAC)
-    , m_mouseDownView(nil)
-    , m_sendingEventToSubview(false)
-    , m_activationEventNumber(-1)
+    , m_hoverTimer(*this, &EventHandler::hoverTimerFired)
+#if ENABLE(CURSOR_SUPPORT)
+    , m_cursorUpdateTimer(*this, &EventHandler::cursorUpdateTimerFired)
+#endif
+    , m_autoscrollController(std::make_unique<AutoscrollController>())
+#if !ENABLE(IOS_TOUCH_EVENTS)
+    , m_fakeMouseMoveEventTimer(*this, &EventHandler::fakeMouseMoveEventTimerFired)
 #endif
-#if ENABLE(TOUCH_EVENTS)
-    , m_originatingTouchPointTargetKey(0)
-    , m_touchPressed(false)
-#endif
-#if ENABLE(GESTURE_EVENTS)
-    , m_scrollGestureHandlingNode(0)
-    , m_lastHitTestResultOverWidget(false)
-#endif
-    , m_maxMouseMovedDuration(0)
-    , m_baseEventType(PlatformEvent::NoType)
-    , m_didStartDrag(false)
-    , m_didLongPressInvokeContextMenu(false)
-    , m_isHandlingWheelEvent(false)
 #if ENABLE(CURSOR_VISIBILITY)
-    , m_autoHideCursorTimer(this, &EventHandler::autoHideCursorTimerFired)
+    , m_autoHideCursorTimer(*this, &EventHandler::autoHideCursorTimerFired)
 #endif
 {
 }
 
 EventHandler::~EventHandler()
 {
+#if !ENABLE(IOS_TOUCH_EVENTS)
     ASSERT(!m_fakeMouseMoveEventTimer.isActive());
+#endif
 #if ENABLE(CURSOR_VISIBILITY)
     ASSERT(!m_autoHideCursorTimer.isActive());
 #endif
@@ -366,7 +402,7 @@ EventHandler::~EventHandler()
 #if ENABLE(DRAG_SUPPORT)
 DragState& EventHandler::dragState()
 {
-    DEFINE_STATIC_LOCAL(DragState, state, ());
+    static NeverDestroyed<DragState> state;
     return state;
 }
 #endif // ENABLE(DRAG_SUPPORT)
@@ -374,64 +410,69 @@ DragState& EventHandler::dragState()
 void EventHandler::clear()
 {
     m_hoverTimer.stop();
+#if ENABLE(CURSOR_SUPPORT)
     m_cursorUpdateTimer.stop();
+#endif
+#if !ENABLE(IOS_TOUCH_EVENTS)
     m_fakeMouseMoveEventTimer.stop();
+#endif
 #if ENABLE(CURSOR_VISIBILITY)
     cancelAutoHideCursorTimer();
 #endif
-    m_resizeLayer = 0;
-    m_nodeUnderMouse = 0;
-    m_lastNodeUnderMouse = 0;
-#if ENABLE(SVG)
-    m_instanceUnderMouse = 0;
-    m_lastInstanceUnderMouse = 0;
-#endif
-    m_lastMouseMoveEventSubframe = 0;
-    m_lastScrollbarUnderMouse = 0;
+    m_resizeLayer = nullptr;
+    m_elementUnderMouse = nullptr;
+    m_lastElementUnderMouse = nullptr;
+    m_lastMouseMoveEventSubframe = nullptr;
+    m_lastScrollbarUnderMouse = nullptr;
     m_clickCount = 0;
-    m_clickNode = 0;
-    m_frameSetBeingResized = 0;
+    m_clickNode = nullptr;
+#if ENABLE(IOS_GESTURE_EVENTS)
+    m_gestureInitialRotation = GestureUnknown;
+#endif
+#if ENABLE(IOS_GESTURE_EVENTS) || ENABLE(MAC_GESTURE_EVENTS)
+    m_gestureInitialDiameter = GestureUnknown;
+    m_gestureLastDiameter = GestureUnknown;
+    m_gestureLastRotation = GestureUnknown;
+    m_gestureTargets.clear();
+#endif
+#if ENABLE(IOS_TOUCH_EVENTS)
+    m_touches.clear();
+    m_firstTouchID = InvalidTouchIdentifier;
+    m_touchEventTargetSubframe = nullptr;
+#endif
+    m_frameSetBeingResized = nullptr;
 #if ENABLE(DRAG_SUPPORT)
-    m_dragTarget = 0;
+    m_dragTarget = nullptr;
     m_shouldOnlyFireDragOverEvent = false;
 #endif
     m_mousePositionIsUnknown = true;
     m_lastKnownMousePosition = IntPoint();
     m_lastKnownMouseGlobalPosition = IntPoint();
-    m_mousePressNode = 0;
+    m_mousePressNode = nullptr;
     m_mousePressed = false;
     m_capturesDragging = false;
-    m_capturingMouseEventsNode = 0;
-    m_latchedWheelEventNode = 0;
-    m_previousWheelScrolledNode = 0;
-#if ENABLE(TOUCH_EVENTS)
+    m_capturingMouseEventsElement = nullptr;
+    clearLatchedState();
+#if ENABLE(TOUCH_EVENTS) && !ENABLE(IOS_TOUCH_EVENTS)
     m_originatingTouchPointTargets.clear();
-    m_originatingTouchPointDocument.clear();
+    m_originatingTouchPointDocument = nullptr;
     m_originatingTouchPointTargetKey = 0;
 #endif
-#if ENABLE(GESTURE_EVENTS)
-    m_scrollGestureHandlingNode = 0;
-    m_lastHitTestResultOverWidget = false;
-    m_previousGestureScrolledNode = 0;
-    m_scrollbarHandlingScrollGesture = 0;
-#endif
     m_maxMouseMovedDuration = 0;
     m_baseEventType = PlatformEvent::NoType;
     m_didStartDrag = false;
-    m_didLongPressInvokeContextMenu = false;
 }
 
-void EventHandler::nodeWillBeRemoved(Node* nodeToBeRemoved)
+void EventHandler::nodeWillBeRemoved(Node& nodeToBeRemoved)
 {
-    if (nodeToBeRemoved->contains(m_clickNode.get()))
-        m_clickNode = 0;
+    if (nodeToBeRemoved.contains(m_clickNode.get()))
+        m_clickNode = nullptr;
 }
 
-static void setSelectionIfNeeded(FrameSelection* selection, const VisibleSelection& newSelection)
+static void setSelectionIfNeeded(FrameSelection& selection, const VisibleSelection& newSelection)
 {
-    ASSERT(selection);
-    if (selection->selection() != newSelection && selection->shouldChangeSelection(newSelection))
-        selection->setSelection(newSelection);
+    if (selection.selection() != newSelection && selection.shouldChangeSelection(newSelection))
+        selection.setSelection(newSelection);
 }
 
 static inline bool dispatchSelectStart(Node* node)
@@ -442,22 +483,30 @@ static inline bool dispatchSelectStart(Node* node)
     return node->dispatchEvent(Event::create(eventNames().selectstartEvent, true, true));
 }
 
-static VisibleSelection expandSelectionToRespectUserSelectAll(Node* targetNode, const VisibleSelection& selection)
+static Node* nodeToSelectOnMouseDownForNode(Node& targetNode)
 {
 #if ENABLE(USERSELECT_ALL)
-    Node* rootUserSelectAll = Position::rootUserSelectAllForNode(targetNode);
-    if (!rootUserSelectAll)
+    if (Node* rootUserSelectAll = Position::rootUserSelectAllForNode(&targetNode))
+        return rootUserSelectAll;
+#endif
+
+    if (targetNode.shouldSelectOnMouseDown())
+        return &targetNode;
+
+    return nullptr;
+}
+
+static VisibleSelection expandSelectionToRespectSelectOnMouseDown(Node& targetNode, const VisibleSelection& selection)
+{
+    Node* nodeToSelect = nodeToSelectOnMouseDownForNode(targetNode);
+    if (!nodeToSelect)
         return selection;
 
     VisibleSelection newSelection(selection);
-    newSelection.setBase(positionBeforeNode(rootUserSelectAll).upstream(CanCrossEditingBoundary));
-    newSelection.setExtent(positionAfterNode(rootUserSelectAll).downstream(CanCrossEditingBoundary));
+    newSelection.setBase(positionBeforeNode(nodeToSelect).upstream(CanCrossEditingBoundary));
+    newSelection.setExtent(positionAfterNode(nodeToSelect).downstream(CanCrossEditingBoundary));
 
     return newSelection;
-#else
-    UNUSED_PARAM(targetNode);
-    return selection;
-#endif
 }
 
 bool EventHandler::updateSelectionForMouseDownDispatchingSelectStart(Node* targetNode, const VisibleSelection& selection, TextGranularity granularity)
@@ -475,18 +524,18 @@ bool EventHandler::updateSelectionForMouseDownDispatchingSelectStart(Node* targe
         m_selectionInitiationState = PlacedCaret;
     }
 
-    m_frame->selection()->setNonDirectionalSelectionIfNeeded(selection, granularity);
+    m_frame.selection().setSelectionByMouseIfDifferent(selection, granularity);
 
     return true;
 }
 
 void EventHandler::selectClosestWordFromHitTestResult(const HitTestResult& result, AppendTrailingWhitespace appendTrailingWhitespace)
 {
-    Node* innerNode = result.targetNode();
+    Node* targetNode = result.targetNode();
     VisibleSelection newSelection;
 
-    if (innerNode && innerNode->renderer()) {
-        VisiblePosition pos(innerNode->renderer()->positionForPoint(result.localPoint()));
+    if (targetNode && targetNode->renderer()) {
+        VisiblePosition pos(targetNode->renderer()->positionForPoint(result.localPoint(), nullptr));
         if (pos.isNotNull()) {
             newSelection = VisibleSelection(pos);
             newSelection.expandUsingGranularity(WordGranularity);
@@ -495,33 +544,73 @@ void EventHandler::selectClosestWordFromHitTestResult(const HitTestResult& resul
         if (appendTrailingWhitespace == ShouldAppendTrailingWhitespace && newSelection.isRange())
             newSelection.appendTrailingWhitespace();
 
-        updateSelectionForMouseDownDispatchingSelectStart(innerNode, expandSelectionToRespectUserSelectAll(innerNode, newSelection), WordGranularity);
+        updateSelectionForMouseDownDispatchingSelectStart(targetNode, expandSelectionToRespectSelectOnMouseDown(*targetNode, newSelection), WordGranularity);
     }
 }
 
+static AppendTrailingWhitespace shouldAppendTrailingWhitespace(const MouseEventWithHitTestResults& result, const Frame& frame)
+{
+    return (result.event().clickCount() == 2 && frame.editor().isSelectTrailingWhitespaceEnabled()) ? ShouldAppendTrailingWhitespace : DontAppendTrailingWhitespace;
+}
+
 void EventHandler::selectClosestWordFromMouseEvent(const MouseEventWithHitTestResults& result)
 {
-    if (m_mouseDownMayStartSelect) {
-        selectClosestWordFromHitTestResult(result.hitTestResult(),
-            (result.event().clickCount() == 2 && m_frame->editor().isSelectTrailingWhitespaceEnabled()) ? ShouldAppendTrailingWhitespace : DontAppendTrailingWhitespace);
-    }
+    if (m_mouseDownMayStartSelect)
+        selectClosestWordFromHitTestResult(result.hitTestResult(), shouldAppendTrailingWhitespace(result, m_frame));
 }
 
-void EventHandler::selectClosestWordOrLinkFromMouseEvent(const MouseEventWithHitTestResults& result)
+#if !PLATFORM(MAC)
+VisibleSelection EventHandler::selectClosestWordFromHitTestResultBasedOnLookup(const HitTestResult&)
+{
+    return VisibleSelection();
+}
+#endif
+    
+void EventHandler::selectClosestContextualWordFromMouseEvent(const MouseEventWithHitTestResults& mouseEvent)
 {
-    if (!result.hitTestResult().isLiveLink())
-        return selectClosestWordFromMouseEvent(result);
+    Node* targetNode = mouseEvent.targetNode();
+    const HitTestResult& result = mouseEvent.hitTestResult();
+    VisibleSelection newSelection;
+    bool appendTrailingWhitespace = shouldAppendTrailingWhitespace(mouseEvent, m_frame);
+    
+    if (targetNode && targetNode->renderer()) {
+        newSelection = selectClosestWordFromHitTestResultBasedOnLookup(result);
+        if (newSelection.isNone()) {
+            VisiblePosition pos(targetNode->renderer()->positionForPoint(result.localPoint(), nullptr));
+            if (pos.isNotNull()) {
+                newSelection = VisibleSelection(pos);
+                newSelection.expandUsingGranularity(WordGranularity);
+            }
+        }
+        
+        if (appendTrailingWhitespace == ShouldAppendTrailingWhitespace && newSelection.isRange())
+            newSelection.appendTrailingWhitespace();
+        
+        updateSelectionForMouseDownDispatchingSelectStart(targetNode, expandSelectionToRespectSelectOnMouseDown(*targetNode, newSelection), WordGranularity);
+    }
+}
+    
+void EventHandler::selectClosestContextualWordOrLinkFromMouseEvent(const MouseEventWithHitTestResults& result)
+{
+    Element* urlElement = result.hitTestResult().URLElement();
+    if (!urlElement || !isDraggableLink(*urlElement)) {
+        if (Node* targetNode = result.targetNode()) {
+            if (isEditableNode(*targetNode))
+                return selectClosestWordFromMouseEvent(result);
+        }
+
+        return selectClosestContextualWordFromMouseEvent(result);
+    }
 
-    Node* innerNode = result.targetNode();
+    Node* targetNode = result.targetNode();
 
-    if (innerNode && innerNode->renderer() && m_mouseDownMayStartSelect) {
+    if (targetNode && targetNode->renderer() && m_mouseDownMayStartSelect) {
         VisibleSelection newSelection;
-        Element* URLElement = result.hitTestResult().URLElement();
-        VisiblePosition pos(innerNode->renderer()->positionForPoint(result.localPoint()));
-        if (pos.isNotNull() && pos.deepEquivalent().deprecatedNode()->isDescendantOf(URLElement))
-            newSelection = VisibleSelection::selectionFromContentsOfNode(URLElement);
+        VisiblePosition pos(targetNode->renderer()->positionForPoint(result.localPoint(), nullptr));
+        if (pos.isNotNull() && pos.deepEquivalent().deprecatedNode()->isDescendantOf(urlElement))
+            newSelection = VisibleSelection::selectionFromContentsOfNode(urlElement);
 
-        updateSelectionForMouseDownDispatchingSelectStart(innerNode, expandSelectionToRespectUserSelectAll(innerNode, newSelection), WordGranularity);
+        updateSelectionForMouseDownDispatchingSelectStart(targetNode, expandSelectionToRespectSelectOnMouseDown(*targetNode, newSelection), WordGranularity);
     }
 }
 
@@ -530,7 +619,7 @@ bool EventHandler::handleMousePressEventDoubleClick(const MouseEventWithHitTestR
     if (event.event().button() != LeftButton)
         return false;
 
-    if (m_frame->selection()->isRange())
+    if (m_frame.selection().isRange())
         // A double-click when range is already selected
         // should not change the selection.  So, do not call
         // selectClosestWordFromMouseEvent, but do set
@@ -548,31 +637,31 @@ bool EventHandler::handleMousePressEventTripleClick(const MouseEventWithHitTestR
     if (event.event().button() != LeftButton)
         return false;
     
-    Node* innerNode = event.targetNode();
-    if (!(innerNode && innerNode->renderer() && m_mouseDownMayStartSelect))
+    Node* targetNode = event.targetNode();
+    if (!(targetNode && targetNode->renderer() && m_mouseDownMayStartSelect))
         return false;
 
     VisibleSelection newSelection;
-    VisiblePosition pos(innerNode->renderer()->positionForPoint(event.localPoint()));
+    VisiblePosition pos(targetNode->renderer()->positionForPoint(event.localPoint(), nullptr));
     if (pos.isNotNull()) {
         newSelection = VisibleSelection(pos);
         newSelection.expandUsingGranularity(ParagraphGranularity);
     }
 
-    return updateSelectionForMouseDownDispatchingSelectStart(innerNode, expandSelectionToRespectUserSelectAll(innerNode, newSelection), ParagraphGranularity);
+    return updateSelectionForMouseDownDispatchingSelectStart(targetNode, expandSelectionToRespectSelectOnMouseDown(*targetNode, newSelection), ParagraphGranularity);
 }
 
 static int textDistance(const Position& start, const Position& end)
 {
-     RefPtr<Range> range = Range::create(start.anchorNode()->document(), start, end);
-     return TextIterator::rangeLength(range.get(), true);
+    RefPtr<Range> range = Range::create(start.anchorNode()->document(), start, end);
+    return TextIterator::rangeLength(range.get(), true);
 }
 
 bool EventHandler::handleMousePressEventSingleClick(const MouseEventWithHitTestResults& event)
 {
-    m_frame->document()->updateLayoutIgnorePendingStylesheets();
-    Node* innerNode = event.targetNode();
-    if (!(innerNode && innerNode->renderer() && m_mouseDownMayStartSelect))
+    m_frame.document()->updateLayoutIgnorePendingStylesheets();
+    Node* targetNode = event.targetNode();
+    if (!(targetNode && targetNode->renderer() && m_mouseDownMayStartSelect))
         return false;
 
     // Extend the selection if the Shift key is down, unless the click is in a link.
@@ -580,24 +669,24 @@ bool EventHandler::handleMousePressEventSingleClick(const MouseEventWithHitTestR
 
     // Don't restart the selection when the mouse is pressed on an
     // existing selection so we can allow for text dragging.
-    if (FrameView* view = m_frame->view()) {
+    if (FrameView* view = m_frame.view()) {
         LayoutPoint vPoint = view->windowToContents(event.event().position());
-        if (!extendSelection && m_frame->selection()->contains(vPoint)) {
+        if (!extendSelection && m_frame.selection().contains(vPoint)) {
             m_mouseDownWasSingleClickInSelection = true;
             return false;
         }
     }
 
-    VisiblePosition visiblePos(innerNode->renderer()->positionForPoint(event.localPoint()));
+    VisiblePosition visiblePos(targetNode->renderer()->positionForPoint(event.localPoint(), nullptr));
     if (visiblePos.isNull())
-        visiblePos = VisiblePosition(firstPositionInOrBeforeNode(innerNode), DOWNSTREAM);
+        visiblePos = VisiblePosition(firstPositionInOrBeforeNode(targetNode), DOWNSTREAM);
     Position pos = visiblePos.deepEquivalent();
 
-    VisibleSelection newSelection = m_frame->selection()->selection();
+    VisibleSelection newSelection = m_frame.selection().selection();
     TextGranularity granularity = CharacterGranularity;
 
     if (extendSelection && newSelection.isCaretOrRange()) {
-        VisibleSelection selectionInUserSelectAll = expandSelectionToRespectUserSelectAll(innerNode, VisibleSelection(pos));
+        VisibleSelection selectionInUserSelectAll = expandSelectionToRespectSelectOnMouseDown(*targetNode, VisibleSelection(pos));
         if (selectionInUserSelectAll.isRange()) {
             if (comparePositions(selectionInUserSelectAll.start(), newSelection.start()) < 0)
                 pos = selectionInUserSelectAll.start();
@@ -605,7 +694,7 @@ bool EventHandler::handleMousePressEventSingleClick(const MouseEventWithHitTestR
                 pos = selectionInUserSelectAll.end();
         }
 
-        if (!m_frame->editor().behavior().shouldConsiderSelectionAsDirectional() && pos.isNotNull()) {
+        if (!m_frame.editor().behavior().shouldConsiderSelectionAsDirectional() && pos.isNotNull()) {
             // See <rdar://problem/3668157> REGRESSION (Mail): shift-click deselects when selection
             // was created right-to-left
             Position start = newSelection.start();
@@ -619,14 +708,14 @@ bool EventHandler::handleMousePressEventSingleClick(const MouseEventWithHitTestR
         } else
             newSelection.setExtent(pos);
 
-        if (m_frame->selection()->granularity() != CharacterGranularity) {
-            granularity = m_frame->selection()->granularity();
-            newSelection.expandUsingGranularity(m_frame->selection()->granularity());
+        if (m_frame.selection().granularity() != CharacterGranularity) {
+            granularity = m_frame.selection().granularity();
+            newSelection.expandUsingGranularity(m_frame.selection().granularity());
         }
     } else
-        newSelection = expandSelectionToRespectUserSelectAll(innerNode, visiblePos);
+        newSelection = expandSelectionToRespectSelectOnMouseDown(*targetNode, visiblePos);
 
-    bool handled = updateSelectionForMouseDownDispatchingSelectStart(innerNode, newSelection, granularity);
+    bool handled = updateSelectionForMouseDownDispatchingSelectStart(targetNode, newSelection, granularity);
 
     if (event.event().button() == MiddleButton) {
         // Ignore handled, since we want to paste to where the caret was placed anyway.
@@ -647,14 +736,16 @@ bool EventHandler::handleMousePressEvent(const MouseEventWithHitTestResults& eve
 {
 #if ENABLE(DRAG_SUPPORT)
     // Reset drag state.
-    dragState().source = 0;
+    dragState().source = nullptr;
 #endif
 
+#if !ENABLE(IOS_TOUCH_EVENTS)
     cancelFakeMouseMoveEvent();
+#endif
 
-    m_frame->document()->updateLayoutIgnorePendingStylesheets();
+    m_frame.document()->updateLayoutIgnorePendingStylesheets();
 
-    if (ScrollView* scrollView = m_frame->view()) {
+    if (ScrollView* scrollView = m_frame.view()) {
         if (scrollView->isPointInScrollbarCorner(event.event().position()))
             return false;
     }
@@ -667,35 +758,38 @@ bool EventHandler::handleMousePressEvent(const MouseEventWithHitTestResults& eve
     
 #if ENABLE(DRAG_SUPPORT)
     // Careful that the drag starting logic stays in sync with eventMayStartDrag()
-    m_mouseDownMayStartDrag = singleClick;
+    // FIXME: eventMayStartDrag() does not check for shift key press, link or image event targets.
+    // Bug: https://bugs.webkit.org/show_bug.cgi?id=155390
+
+    // Single mouse down on links or images can always trigger drag-n-drop.
+    bool isMouseDownOnLinkOrImage = event.isOverLink() || event.hitTestResult().image();
+    m_mouseDownMayStartDrag = singleClick && (!event.event().shiftKey() || isMouseDownOnLinkOrImage);
 #endif
 
     m_mouseDownWasSingleClickInSelection = false;
 
     m_mouseDown = event.event();
 
+    if (m_immediateActionStage != ImmediateActionStage::PerformedHitTest)
+        m_immediateActionStage = ImmediateActionStage::None;
+
     if (event.isOverWidget() && passWidgetMouseDownEventToWidget(event))
         return true;
 
-#if ENABLE(SVG)
-    if (m_frame->document()->isSVGDocument()
-        && toSVGDocument(m_frame->document())->zoomAndPanEnabled()) {
+    if (is<SVGDocument>(*m_frame.document()) && downcast<SVGDocument>(*m_frame.document()).zoomAndPanEnabled()) {
         if (event.event().shiftKey() && singleClick) {
             m_svgPan = true;
-            toSVGDocument(m_frame->document())->startPan(m_frame->view()->windowToContents(event.event().position()));
+            downcast<SVGDocument>(*m_frame.document()).startPan(m_frame.view()->windowToContents(event.event().position()));
             return true;
         }
     }
-#endif
 
     // We don't do this at the start of mouse down handling,
     // because we don't want to do it until we know we didn't hit a widget.
     if (singleClick)
         focusDocumentView();
 
-    Node* innerNode = event.targetNode();
-
-    m_mousePressNode = innerNode;
+    m_mousePressNode = event.targetNode();
 #if ENABLE(DRAG_SUPPORT)
     m_dragStartPos = event.event().position();
 #endif
@@ -732,7 +826,7 @@ bool EventHandler::handleMouseDraggedEvent(const MouseEventWithHitTestResults& e
 
     RenderObject* renderer = targetNode->renderer();
     if (!renderer) {
-        Node* parent = EventPathWalker::parent(targetNode);
+        Element* parent = targetNode->parentOrShadowHostElement();
         if (!parent)
             return false;
 
@@ -741,7 +835,7 @@ bool EventHandler::handleMouseDraggedEvent(const MouseEventWithHitTestResults& e
             return false;
     }
 
-#if PLATFORM(MAC) // FIXME: Why does this assertion fire on other platforms?
+#if PLATFORM(COCOA) // FIXME: Why does this assertion fire on other platforms?
     ASSERT(m_mouseDownMayStartSelect || m_mouseDownMayStartAutoscroll);
 #endif
 
@@ -753,9 +847,8 @@ bool EventHandler::handleMouseDraggedEvent(const MouseEventWithHitTestResults& e
     }
 
     if (m_selectionInitiationState != ExtendedSelection) {
-        HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::Active | HitTestRequest::DisallowShadowContent);
         HitTestResult result(m_mouseDownPos);
-        m_frame->document()->renderView()->hitTest(request, result);
+        m_frame.document()->renderView()->hitTest(HitTestRequest(), result);
 
         updateSelectionForMouseDrag(result);
     }
@@ -768,47 +861,47 @@ bool EventHandler::eventMayStartDrag(const PlatformMouseEvent& event) const
     // This is a pre-flight check of whether the event might lead to a drag being started.  Be careful
     // that its logic needs to stay in sync with handleMouseMoveEvent() and the way we setMouseDownMayStartDrag
     // in handleMousePressEvent
-    
-    if (!m_frame->contentRenderer() || !m_frame->contentRenderer()->hasLayer())
+    RenderView* renderView = m_frame.contentRenderer();
+    if (!renderView)
         return false;
 
     if (event.button() != LeftButton || event.clickCount() != 1)
         return false;
-    
-    FrameView* view = m_frame->view();
+
+    FrameView* view = m_frame.view();
     if (!view)
         return false;
 
-    Page* page = m_frame->page();
+    Page* page = m_frame.page();
     if (!page)
         return false;
 
     updateDragSourceActionsAllowed();
     HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::DisallowShadowContent);
     HitTestResult result(view->windowToContents(event.position()));
-    m_frame->contentRenderer()->hitTest(request, result);
+    renderView->hitTest(request, result);
     DragState state;
-    return result.innerElement() && page->dragController()->draggableElement(m_frame, result.innerElement(), result.roundedPointInInnerNodeFrame(), state);
+    return result.innerElement() && page->dragController().draggableElement(&m_frame, result.innerElement(), result.roundedPointInInnerNodeFrame(), state);
 }
 
 void EventHandler::updateSelectionForMouseDrag()
 {
-    FrameView* view = m_frame->view();
+    FrameView* view = m_frame.view();
     if (!view)
         return;
-    RenderView* renderer = m_frame->contentRenderer();
-    if (!renderer)
+    RenderView* renderView = m_frame.contentRenderer();
+    if (!renderView)
         return;
 
     HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::Active | HitTestRequest::Move | HitTestRequest::DisallowShadowContent);
     HitTestResult result(view->windowToContents(m_lastKnownMousePosition));
-    renderer->hitTest(request, result);
+    renderView->hitTest(request, result);
     updateSelectionForMouseDrag(result);
 }
 
 static VisiblePosition selectionExtentRespectingEditingBoundary(const VisibleSelection& selection, const LayoutPoint& localPoint, Node* targetNode)
 {
-    LayoutPoint selectionEndPoint = localPoint;
+    FloatPoint selectionEndPoint = localPoint;
     Element* editableElement = selection.rootEditableElement();
 
     if (!targetNode->renderer())
@@ -819,11 +912,11 @@ static VisiblePosition selectionExtentRespectingEditingBoundary(const VisibleSel
             return VisiblePosition();
 
         FloatPoint absolutePoint = targetNode->renderer()->localToAbsolute(FloatPoint(selectionEndPoint));
-        selectionEndPoint = roundedLayoutPoint(editableElement->renderer()->absoluteToLocal(absolutePoint));
+        selectionEndPoint = editableElement->renderer()->absoluteToLocal(absolutePoint);
         targetNode = editableElement;
     }
 
-    return targetNode->renderer()->positionForPoint(selectionEndPoint);
+    return targetNode->renderer()->positionForPoint(LayoutPoint(selectionEndPoint), nullptr);
 }
 
 void EventHandler::updateSelectionForMouseDrag(const HitTestResult& hitTestResult)
@@ -835,7 +928,7 @@ void EventHandler::updateSelectionForMouseDrag(const HitTestResult& hitTestResul
     if (!target)
         return;
 
-    VisiblePosition targetPosition = selectionExtentRespectingEditingBoundary(m_frame->selection()->selection(), hitTestResult.localPoint(), target);
+    VisiblePosition targetPosition = selectionExtentRespectingEditingBoundary(m_frame.selection().selection(), hitTestResult.localPoint(), target);
 
     // Don't modify the selection if we're not on a node.
     if (targetPosition.isNull())
@@ -843,9 +936,8 @@ void EventHandler::updateSelectionForMouseDrag(const HitTestResult& hitTestResul
 
     // Restart the selection if this is the first mouse move. This work is usually
     // done in handleMousePressEvent, but not if the mouse press was on an existing selection.
-    VisibleSelection newSelection = m_frame->selection()->selection();
+    VisibleSelection newSelection = m_frame.selection().selection();
 
-#if ENABLE(SVG)
     // Special case to limit selection to the containing block for SVG text.
     // FIXME: Isn't there a better non-SVG-specific way to do this?
     if (Node* selectionBaseNode = newSelection.base().deprecatedNode())
@@ -853,7 +945,6 @@ void EventHandler::updateSelectionForMouseDrag(const HitTestResult& hitTestResul
             if (selectionBaseRenderer->isSVGText())
                 if (target->renderer()->containingBlock() != selectionBaseRenderer->containingBlock())
                     return;
-#endif
 
     if (m_selectionInitiationState == HaveNotStartedSelection && !dispatchSelectStart(target))
         return;
@@ -871,11 +962,11 @@ void EventHandler::updateSelectionForMouseDrag(const HitTestResult& hitTestResul
         newSelection.setExtent(positionAfterNode(rootUserSelectAllForMousePressNode).downstream(CanCrossEditingBoundary));
     } else {
         // Reset base for user select all when base is inside user-select-all area and extent < base.
-        if (rootUserSelectAllForMousePressNode && comparePositions(target->renderer()->positionForPoint(hitTestResult.localPoint()), m_mousePressNode->renderer()->positionForPoint(m_dragStartPos)) < 0)
+        if (rootUserSelectAllForMousePressNode && comparePositions(target->renderer()->positionForPoint(hitTestResult.localPoint(), nullptr), m_mousePressNode->renderer()->positionForPoint(m_dragStartPos, nullptr)) < 0)
             newSelection.setBase(positionAfterNode(rootUserSelectAllForMousePressNode).downstream(CanCrossEditingBoundary));
         
         Node* rootUserSelectAllForTarget = Position::rootUserSelectAllForNode(target);
-        if (rootUserSelectAllForTarget && m_mousePressNode->renderer() && comparePositions(target->renderer()->positionForPoint(hitTestResult.localPoint()), m_mousePressNode->renderer()->positionForPoint(m_dragStartPos)) < 0)
+        if (rootUserSelectAllForTarget && m_mousePressNode->renderer() && comparePositions(target->renderer()->positionForPoint(hitTestResult.localPoint(), nullptr), m_mousePressNode->renderer()->positionForPoint(m_dragStartPos, nullptr)) < 0)
             newSelection.setExtent(positionBeforeNode(rootUserSelectAllForTarget).upstream(CanCrossEditingBoundary));
         else if (rootUserSelectAllForTarget && m_mousePressNode->renderer())
             newSelection.setExtent(positionAfterNode(rootUserSelectAllForTarget).downstream(CanCrossEditingBoundary));
@@ -886,17 +977,17 @@ void EventHandler::updateSelectionForMouseDrag(const HitTestResult& hitTestResul
     newSelection.setExtent(targetPosition);
 #endif
 
-    if (m_frame->selection()->granularity() != CharacterGranularity)
-        newSelection.expandUsingGranularity(m_frame->selection()->granularity());
+    if (m_frame.selection().granularity() != CharacterGranularity)
+        newSelection.expandUsingGranularity(m_frame.selection().granularity());
 
-    m_frame->selection()->setNonDirectionalSelectionIfNeeded(newSelection, m_frame->selection()->granularity(),
+    m_frame.selection().setSelectionByMouseIfDifferent(newSelection, m_frame.selection().granularity(),
         FrameSelection::AdjustEndpointsAtBidiBoundary);
 }
 #endif // ENABLE(DRAG_SUPPORT)
 
 void EventHandler::lostMouseCapture()
 {
-    m_frame->selection()->setCaretBlinkingSuspended(false);
+    m_frame.selection().setCaretBlinkingSuspended(false);
 }
 
 bool EventHandler::handleMouseUp(const MouseEventWithHitTestResults& event)
@@ -941,25 +1032,21 @@ bool EventHandler::handleMouseReleaseEvent(const MouseEventWithHitTestResults& e
 #if ENABLE(DRAG_SUPPORT)
             && m_dragStartPos == event.event().position()
 #endif
-            && m_frame->selection()->isRange()
+            && m_frame.selection().isRange()
             && event.event().button() != RightButton) {
         VisibleSelection newSelection;
         Node* node = event.targetNode();
-        bool caretBrowsing = m_frame->settings() && m_frame->settings()->caretBrowsingEnabled();
-        if (node && (caretBrowsing || node->rendererIsEditable()) && node->renderer()) {
-            VisiblePosition pos = node->renderer()->positionForPoint(event.localPoint());
+        bool caretBrowsing = m_frame.settings().caretBrowsingEnabled();
+        if (node && node->renderer() && (caretBrowsing || node->hasEditableStyle())) {
+            VisiblePosition pos = node->renderer()->positionForPoint(event.localPoint(), nullptr);
             newSelection = VisibleSelection(pos);
         }
 
-        setSelectionIfNeeded(m_frame->selection(), newSelection);
+        setSelectionIfNeeded(m_frame.selection(), newSelection);
 
         handled = true;
     }
 
-    m_frame->selection()->notifyRendererOfSelectionChange(UserTriggered);
-
-    m_frame->selection()->selectFrameElementInParentIfFullySelected();
-
     if (event.event().button() == MiddleButton) {
         // Ignore handled, since we want to paste to where the caret was placed anyway.
         handled = handlePasteGlobalSelection(event.event()) || handled;
@@ -980,17 +1067,19 @@ void EventHandler::didPanScrollStop()
     m_autoscrollController->didPanScrollStop();
 }
 
-void EventHandler::startPanScrolling(RenderObject* renderer)
+void EventHandler::startPanScrolling(RenderElement* renderer)
 {
-    if (!renderer->isBox())
+#if !PLATFORM(IOS)
+    if (!is<RenderBox>(*renderer))
         return;
-    m_autoscrollController->startPanScrolling(toRenderBox(renderer), lastKnownMousePosition());
+    m_autoscrollController->startPanScrolling(downcast<RenderBox>(renderer), lastKnownMousePosition());
     invalidateClick();
+#endif
 }
 
 #endif // ENABLE(PAN_SCROLLING)
 
-RenderObject* EventHandler::autoscrollRenderer() const
+RenderBox* EventHandler::autoscrollRenderer() const
 {
     return m_autoscrollController->autoscrollRenderer();
 }
@@ -1013,18 +1102,15 @@ bool EventHandler::panScrollInProgress() const
 #if ENABLE(DRAG_SUPPORT)
 DragSourceAction EventHandler::updateDragSourceActionsAllowed() const
 {
-    if (!m_frame)
-        return DragSourceActionNone;
-
-    Page* page = m_frame->page();
+    Page* page = m_frame.page();
     if (!page)
         return DragSourceActionNone;
 
-    FrameView* view = m_frame->view();
+    FrameView* view = m_frame.view();
     if (!view)
         return DragSourceActionNone;
 
-    return page->dragController()->delegateDragSourceAction(view->contentsToRootView(m_mouseDownPos));
+    return page->dragController().delegateDragSourceAction(view->contentsToRootView(m_mouseDownPos));
 }
 #endif // ENABLE(DRAG_SUPPORT)
 
@@ -1032,28 +1118,29 @@ HitTestResult EventHandler::hitTestResultAtPoint(const LayoutPoint& point, HitTe
 {
     // We always send hitTestResultAtPoint to the main frame if we have one,
     // otherwise we might hit areas that are obscured by higher frames.
-    if (Page* page = m_frame->page()) {
-        Frame* mainFrame = page->mainFrame();
-        if (m_frame != mainFrame) {
-            FrameView* frameView = m_frame->view();
-            FrameView* mainView = mainFrame->view();
-            if (frameView && mainView) {
-                IntPoint mainFramePoint = mainView->rootViewToContents(frameView->contentsToRootView(roundedIntPoint(point)));
-                return mainFrame->eventHandler()->hitTestResultAtPoint(mainFramePoint, hitType, padding);
-            }
+    if (!m_frame.isMainFrame()) {
+        Frame& mainFrame = m_frame.mainFrame();
+        FrameView* frameView = m_frame.view();
+        FrameView* mainView = mainFrame.view();
+        if (frameView && mainView) {
+            IntPoint mainFramePoint = mainView->rootViewToContents(frameView->contentsToRootView(roundedIntPoint(point)));
+            return mainFrame.eventHandler().hitTestResultAtPoint(mainFramePoint, hitType, padding);
         }
     }
 
     HitTestResult result(point, padding.height(), padding.width(), padding.height(), padding.width());
 
-    if (!m_frame->contentRenderer())
+    RenderView* renderView = m_frame.contentRenderer();
+    if (!renderView)
         return result;
-
+    
+    // We should always start hittesting a clean tree.
+    renderView->document().updateLayoutIgnorePendingStylesheets();
     // hitTestResultAtPoint is specifically used to hitTest into all frames, thus it always allows child frame content.
     HitTestRequest request(hitType | HitTestRequest::AllowChildFrameContent);
-    m_frame->contentRenderer()->hitTest(request, result);
+    renderView->hitTest(request, result);
     if (!request.readOnly())
-        m_frame->document()->updateHoverActiveState(request, result.innerElement());
+        m_frame.document()->updateHoverActiveState(request, result.innerElement());
 
     if (request.disallowsShadowContent())
         result.setToNonShadowAncestor();
@@ -1066,29 +1153,19 @@ void EventHandler::stopAutoscrollTimer(bool rendererIsBeingDestroyed)
     m_autoscrollController->stopAutoscrollTimer(rendererIsBeingDestroyed);
 }
 
-Node* EventHandler::mousePressNode() const
-{
-    return m_mousePressNode.get();
-}
-
-void EventHandler::setMousePressNode(PassRefPtr<Node> node)
-{
-    m_mousePressNode = node;
-}
-
 bool EventHandler::scrollOverflow(ScrollDirection direction, ScrollGranularity granularity, Node* startingNode)
 {
     Node* node = startingNode;
 
     if (!node)
-        node = m_frame->document()->focusedElement();
+        node = m_frame.document()->focusedElement();
 
     if (!node)
         node = m_mousePressNode.get();
     
     if (node) {
-        RenderObject* r = node->renderer();
-        if (r && !r->isListBox() && r->enclosingBox()->scroll(direction, granularity)) {
+        auto r = node->renderer();
+        if (r && !r->isListBox() && r->enclosingBox().scroll(direction, granularity)) {
             setFrameWasScrolledByUser();
             return true;
         }
@@ -1102,14 +1179,14 @@ bool EventHandler::logicalScrollOverflow(ScrollLogicalDirection direction, Scrol
     Node* node = startingNode;
 
     if (!node)
-        node = m_frame->document()->focusedElement();
+        node = m_frame.document()->focusedElement();
 
     if (!node)
         node = m_mousePressNode.get();
     
     if (node) {
-        RenderObject* r = node->renderer();
-        if (r && !r->isListBox() && r->enclosingBox()->logicalScroll(direction, granularity)) {
+        auto r = node->renderer();
+        if (r && !r->isListBox() && r->enclosingBox().logicalScroll(direction, granularity)) {
             setFrameWasScrolledByUser();
             return true;
         }
@@ -1122,31 +1199,31 @@ bool EventHandler::scrollRecursively(ScrollDirection direction, ScrollGranularit
 {
     // The layout needs to be up to date to determine if we can scroll. We may be
     // here because of an onLoad event, in which case the final layout hasn't been performed yet.
-    m_frame->document()->updateLayoutIgnorePendingStylesheets();
+    m_frame.document()->updateLayoutIgnorePendingStylesheets();
     if (scrollOverflow(direction, granularity, startingNode))
         return true;    
-    Frame* frame = m_frame;
+    Frame* frame = &m_frame;
     FrameView* view = frame->view();
     if (view && view->scroll(direction, granularity))
         return true;
-    frame = frame->tree()->parent();
+    frame = frame->tree().parent();
     if (!frame)
         return false;
-    return frame->eventHandler()->scrollRecursively(direction, granularity, m_frame->ownerElement());
+    return frame->eventHandler().scrollRecursively(direction, granularity, m_frame.ownerElement());
 }
 
 bool EventHandler::logicalScrollRecursively(ScrollLogicalDirection direction, ScrollGranularity granularity, Node* startingNode)
 {
     // The layout needs to be up to date to determine if we can scroll. We may be
     // here because of an onLoad event, in which case the final layout hasn't been performed yet.
-    m_frame->document()->updateLayoutIgnorePendingStylesheets();
+    m_frame.document()->updateLayoutIgnorePendingStylesheets();
     if (logicalScrollOverflow(direction, granularity, startingNode))
         return true;    
-    Frame* frame = m_frame;
+    Frame* frame = &m_frame;
     FrameView* view = frame->view();
     
     bool scrolled = false;
-#if PLATFORM(MAC)
+#if PLATFORM(COCOA)
     // Mac also resets the scroll position in the inline direction.
     if (granularity == ScrollByDocument && view && view->logicalScroll(ScrollInlineDirectionBackward, ScrollByDocument))
         scrolled = true;
@@ -1157,11 +1234,11 @@ bool EventHandler::logicalScrollRecursively(ScrollLogicalDirection direction, Sc
     if (scrolled)
         return true;
     
-    frame = frame->tree()->parent();
+    frame = frame->tree().parent();
     if (!frame)
         return false;
 
-    return frame->eventHandler()->logicalScrollRecursively(direction, granularity, m_frame->ownerElement());
+    return frame->eventHandler().logicalScrollRecursively(direction, granularity, m_frame.ownerElement());
 }
 
 IntPoint EventHandler::lastKnownMousePosition() const
@@ -1179,28 +1256,29 @@ Frame* EventHandler::subframeForHitTestResult(const MouseEventWithHitTestResults
 Frame* EventHandler::subframeForTargetNode(Node* node)
 {
     if (!node)
-        return 0;
+        return nullptr;
 
-    RenderObject* renderer = node->renderer();
-    if (!renderer || !renderer->isWidget())
-        return 0;
+    auto renderer = node->renderer();
+    if (!is<RenderWidget>(renderer))
+        return nullptr;
 
-    Widget* widget = toRenderWidget(renderer)->widget();
-    if (!widget || !widget->isFrameView())
-        return 0;
+    Widget* widget = downcast<RenderWidget>(*renderer).widget();
+    if (!is<FrameView>(widget))
+        return nullptr;
 
-    return toFrameView(widget)->frame();
+    return &downcast<FrameView>(*widget).frame();
 }
 
+#if ENABLE(CURSOR_SUPPORT)
 static bool isSubmitImage(Node* node)
 {
-    return node && isHTMLInputElement(node) && toHTMLInputElement(node)->isImageButton();
+    return is<HTMLInputElement>(node) && downcast<HTMLInputElement>(*node).isImageButton();
 }
 
 // Returns true if the node's editable block is not current focused for editing
-static bool nodeIsNotBeingEdited(Node* node, Frame* frame)
+static bool nodeIsNotBeingEdited(const Node& node, const Frame& frame)
 {
-    return frame->selection()->rootEditableElement() != node->rootEditableElement();
+    return frame.selection().selection().rootEditableElement() != node.rootEditableElement();
 }
 
 bool EventHandler::useHandCursor(Node* node, bool isOverLink, bool shiftKey)
@@ -1208,13 +1286,12 @@ bool EventHandler::useHandCursor(Node* node, bool isOverLink, bool shiftKey)
     if (!node)
         return false;
 
-    bool editable = node->rendererIsEditable();
+    bool editable = node->hasEditableStyle();
     bool editableLinkEnabled = false;
 
     // If the link is editable, then we need to check the settings to see whether or not the link should be followed
     if (editable) {
-        ASSERT(m_frame->settings());
-        switch (m_frame->settings()->editableLinkBehavior()) {
+        switch (m_frame.settings().editableLinkBehavior()) {
         default:
         case EditableLinkDefaultBehavior:
         case EditableLinkAlwaysLive:
@@ -1226,7 +1303,7 @@ bool EventHandler::useHandCursor(Node* node, bool isOverLink, bool shiftKey)
             break;
 
         case EditableLinkLiveWhenNotFocused:
-            editableLinkEnabled = nodeIsNotBeingEdited(node, m_frame) || shiftKey;
+            editableLinkEnabled = nodeIsNotBeingEdited(*node, m_frame) || shiftKey;
             break;
 
         case EditableLinkOnlyLiveWithShiftKey:
@@ -1238,11 +1315,9 @@ bool EventHandler::useHandCursor(Node* node, bool isOverLink, bool shiftKey)
     return ((isOverLink || isSubmitImage(node)) && (!editable || editableLinkEnabled));
 }
 
-void EventHandler::cursorUpdateTimerFired(Timer<EventHandler>*)
+void EventHandler::cursorUpdateTimerFired()
 {
-    ASSERT(m_frame);
-    ASSERT(m_frame->document());
-
+    ASSERT(m_frame.document());
     updateCursor();
 }
 
@@ -1251,7 +1326,7 @@ void EventHandler::updateCursor()
     if (m_mousePositionIsUnknown)
         return;
 
-    FrameView* view = m_frame->view();
+    FrameView* view = m_frame.view();
     if (!view)
         return;
 
@@ -1268,9 +1343,7 @@ void EventHandler::updateCursor()
     bool metaKey;
     PlatformKeyboardEvent::getCurrentModifierState(shiftKey, ctrlKey, altKey, metaKey);
 
-    m_frame->document()->updateLayout();
-
-    HitTestRequest request(HitTestRequest::ReadOnly);
+    HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::AllowFrameScrollbars);
     HitTestResult result(view->windowToContents(m_lastKnownMousePosition));
     renderView->hitTest(request, result);
 
@@ -1286,40 +1359,38 @@ OptionalCursor EventHandler::selectCursor(const HitTestResult& result, bool shif
     if (m_resizeLayer && m_resizeLayer->inResizeMode())
         return NoCursorChange;
 
-    Page* page = m_frame->page();
-    if (!page)
+    if (!m_frame.page())
         return NoCursorChange;
+
 #if ENABLE(PAN_SCROLLING)
-    if (page->mainFrame()->eventHandler()->panScrollInProgress())
+    if (m_frame.mainFrame().eventHandler().panScrollInProgress())
         return NoCursorChange;
 #endif
 
+    // Use always pointer cursor for scrollbars.
+    if (result.scrollbar()) {
+#if ENABLE(CURSOR_VISIBILITY)
+        cancelAutoHideCursorTimer();
+#endif
+        return pointerCursor();
+    }
+
     Node* node = result.targetNode();
     if (!node)
         return NoCursorChange;
 
-    RenderObject* renderer = node->renderer();
-    RenderStyle* style = renderer ? renderer->style() : 0;
+    auto renderer = node->renderer();
+    RenderStyle* style = renderer ? &renderer->style() : nullptr;
     bool horizontalText = !style || style->isHorizontalWritingMode();
     const Cursor& iBeam = horizontalText ? iBeamCursor() : verticalTextCursor();
 
 #if ENABLE(CURSOR_VISIBILITY)
-    if (style && style->cursorVisibility() == CursorVisibilityAutoHide) {
-        FeatureObserver::observe(m_frame->document(), FeatureObserver::CursorVisibility);
+    if (style && style->cursorVisibility() == CursorVisibilityAutoHide)
         startAutoHideCursorTimer();
-    } else
+    else
         cancelAutoHideCursorTimer();
 #endif
 
-    // During selection, use an I-beam no matter what we're over.
-    // If a drag may be starting or we're capturing mouse events for a particular node, don't treat this as a selection.
-    if (m_mousePressed && m_mouseDownMayStartSelect
-#if ENABLE(DRAG_SUPPORT)
-        && !m_mouseDownMayStartDrag
-#endif
-        && m_frame->selection()->isCaretOrRange() && !m_capturingMouseEventsNode)
-        return iBeam;
-
     if (renderer) {
         Cursor overrideCursor;
         switch (renderer->getCursor(roundedIntPoint(result.localPoint()), overrideCursor)) {
@@ -1344,8 +1415,7 @@ OptionalCursor EventHandler::selectCursor(const HitTestResult& result, bool shif
             float scale = styleImage->imageScaleFactor();
             // Get hotspot and convert from logical pixels to physical pixels.
             IntPoint hotSpot = (*cursors)[i].hotSpot();
-            hotSpot.scale(scale, scale);
-            IntSize size = cachedImage->imageForRenderer(renderer)->size();
+            FloatSize size = cachedImage->imageForRenderer(renderer)->size();
             if (cachedImage->errorOccurred())
                 continue;
             // Limit the size of cursors (in UI pixels) so that they cannot be
@@ -1367,9 +1437,20 @@ OptionalCursor EventHandler::selectCursor(const HitTestResult& result, bool shif
         }
     }
 
-    switch (style ? style->cursor() : CURSOR_AUTO) {
-    case CURSOR_AUTO: {
-        bool editable = node->rendererIsEditable();
+    // During selection, use an I-beam regardless of the content beneath the cursor.
+    // If a drag may be starting or we're capturing mouse events for a particular node, don't treat this as a selection.
+    if (m_mousePressed
+        && m_mouseDownMayStartSelect
+#if ENABLE(DRAG_SUPPORT)
+        && !m_mouseDownMayStartDrag
+#endif
+        && m_frame.selection().isCaretOrRange()
+        && !m_capturingMouseEventsElement)
+        return iBeam;
+
+    switch (style ? style->cursor() : CursorAuto) {
+    case CursorAuto: {
+        bool editable = node->hasEditableStyle();
 
         if (useHandCursor(node, result.isOverLink(), shiftKey))
             return handCursor();
@@ -1377,101 +1458,105 @@ OptionalCursor EventHandler::selectCursor(const HitTestResult& result, bool shif
         bool inResizer = false;
         if (renderer) {
             if (RenderLayer* layer = renderer->enclosingLayer()) {
-                if (FrameView* view = m_frame->view())
+                if (FrameView* view = m_frame.view())
                     inResizer = layer->isPointInResizeControl(view->windowToContents(roundedIntPoint(result.localPoint())));
             }
         }
+
         if ((editable || (renderer && renderer->isText() && node->canStartSelection())) && !inResizer && !result.scrollbar())
             return iBeam;
         return pointerCursor();
     }
-    case CURSOR_CROSS:
+    case CursorCross:
         return crossCursor();
-    case CURSOR_POINTER:
+    case CursorPointer:
         return handCursor();
-    case CURSOR_MOVE:
+    case CursorMove:
         return moveCursor();
-    case CURSOR_ALL_SCROLL:
+    case CursorAllScroll:
         return moveCursor();
-    case CURSOR_E_RESIZE:
+    case CursorEResize:
         return eastResizeCursor();
-    case CURSOR_W_RESIZE:
+    case CursorWResize:
         return westResizeCursor();
-    case CURSOR_N_RESIZE:
+    case CursorNResize:
         return northResizeCursor();
-    case CURSOR_S_RESIZE:
+    case CursorSResize:
         return southResizeCursor();
-    case CURSOR_NE_RESIZE:
+    case CursorNeResize:
         return northEastResizeCursor();
-    case CURSOR_SW_RESIZE:
+    case CursorSwResize:
         return southWestResizeCursor();
-    case CURSOR_NW_RESIZE:
+    case CursorNwResize:
         return northWestResizeCursor();
-    case CURSOR_SE_RESIZE:
+    case CursorSeResize:
         return southEastResizeCursor();
-    case CURSOR_NS_RESIZE:
+    case CursorNsResize:
         return northSouthResizeCursor();
-    case CURSOR_EW_RESIZE:
+    case CursorEwResize:
         return eastWestResizeCursor();
-    case CURSOR_NESW_RESIZE:
+    case CursorNeswResize:
         return northEastSouthWestResizeCursor();
-    case CURSOR_NWSE_RESIZE:
+    case CursorNwseResize:
         return northWestSouthEastResizeCursor();
-    case CURSOR_COL_RESIZE:
+    case CursorColResize:
         return columnResizeCursor();
-    case CURSOR_ROW_RESIZE:
+    case CursorRowResize:
         return rowResizeCursor();
-    case CURSOR_TEXT:
+    case CursorText:
         return iBeamCursor();
-    case CURSOR_WAIT:
+    case CursorWait:
         return waitCursor();
-    case CURSOR_HELP:
+    case CursorHelp:
         return helpCursor();
-    case CURSOR_VERTICAL_TEXT:
+    case CursorVerticalText:
         return verticalTextCursor();
-    case CURSOR_CELL:
+    case CursorCell:
         return cellCursor();
-    case CURSOR_CONTEXT_MENU:
+    case CursorContextMenu:
         return contextMenuCursor();
-    case CURSOR_PROGRESS:
+    case CursorProgress:
         return progressCursor();
-    case CURSOR_NO_DROP:
+    case CursorNoDrop:
         return noDropCursor();
-    case CURSOR_ALIAS:
+    case CursorAlias:
         return aliasCursor();
-    case CURSOR_COPY:
+    case CursorCopy:
         return copyCursor();
-    case CURSOR_NONE:
+    case CursorNone:
         return noneCursor();
-    case CURSOR_NOT_ALLOWED:
+    case CursorNotAllowed:
         return notAllowedCursor();
-    case CURSOR_DEFAULT:
+    case CursorDefault:
         return pointerCursor();
-    case CURSOR_WEBKIT_ZOOM_IN:
+    case CursorZoomIn:
         return zoomInCursor();
-    case CURSOR_WEBKIT_ZOOM_OUT:
+    case CursorZoomOut:
         return zoomOutCursor();
-    case CURSOR_WEBKIT_GRAB:
+    case CursorWebkitGrab:
         return grabCursor();
-    case CURSOR_WEBKIT_GRABBING:
+    case CursorWebkitGrabbing:
         return grabbingCursor();
     }
     return pointerCursor();
 }
+#endif // ENABLE(CURSOR_SUPPORT)
 
 #if ENABLE(CURSOR_VISIBILITY)
 void EventHandler::startAutoHideCursorTimer()
 {
-    Page* page = m_frame->page();
+    Page* page = m_frame.page();
     if (!page)
         return;
 
-    m_autoHideCursorTimer.startOneShot(page->settings()->timeWithoutMouseMovementBeforeHidingControls());
+    m_autoHideCursorTimer.startOneShot(page->settings().timeWithoutMouseMovementBeforeHidingControls());
 
+#if !ENABLE(IOS_TOUCH_EVENTS)
     // The fake mouse move event screws up the auto-hide feature (by resetting the auto-hide timer)
     // so cancel any pending fake mouse moves.
     if (m_fakeMouseMoveEventTimer.isActive())
         m_fakeMouseMoveEventTimer.stop();
+#endif
 }
 
 void EventHandler::cancelAutoHideCursorTimer()
@@ -1480,56 +1565,70 @@ void EventHandler::cancelAutoHideCursorTimer()
         m_autoHideCursorTimer.stop();
 }
 
-void EventHandler::autoHideCursorTimerFired(Timer<EventHandler>* timer)
+void EventHandler::autoHideCursorTimerFired()
 {
-    ASSERT_UNUSED(timer, timer == &m_autoHideCursorTimer);
     m_currentMouseCursor = noneCursor();
-    FrameView* view = m_frame->view();
+    FrameView* view = m_frame.view();
     if (view && view->isActive())
         view->setCursor(m_currentMouseCursor);
 }
 #endif
 
-static LayoutPoint documentPointForWindowPoint(Frame* frame, const IntPoint& windowPoint)
+static LayoutPoint documentPointForWindowPoint(Frame& frame, const IntPoint& windowPoint)
 {
-    FrameView* view = frame->view();
+    FrameView* view = frame.view();
     // FIXME: Is it really OK to use the wrong coordinates here when view is 0?
     // Historically the code would just crash; this is clearly no worse than that.
     return view ? view->windowToContents(windowPoint) : windowPoint;
 }
 
-bool EventHandler::handleMousePressEvent(const PlatformMouseEvent& mouseEvent)
+static Scrollbar* scrollbarForMouseEvent(const MouseEventWithHitTestResults& mouseEvent, FrameView* view)
+{
+    if (view) {
+        if (auto* scrollbar = view->scrollbarAtPoint(mouseEvent.event().position()))
+            return scrollbar;
+    }
+    return mouseEvent.scrollbar();
+
+}
+
+bool EventHandler::handleMousePressEvent(const PlatformMouseEvent& platformMouseEvent)
 {
-    RefPtr<FrameView> protector(m_frame->view());
+    RefPtr<FrameView> protector(m_frame.view());
 
-    if (InspectorInstrumentation::handleMousePress(m_frame->page())) {
+    if (InspectorInstrumentation::handleMousePress(m_frame)) {
         invalidateClick();
         return true;
     }
 
+    if (m_frame.mainFrame().pageOverlayController().handleMouseEvent(platformMouseEvent))
+        return true;
+
 #if ENABLE(TOUCH_EVENTS)
-    bool defaultPrevented = dispatchSyntheticTouchEventIfEnabled(mouseEvent);
+    bool defaultPrevented = dispatchSyntheticTouchEventIfEnabled(platformMouseEvent);
     if (defaultPrevented)
         return true;
 #endif
 
-    UserGestureIndicator gestureIndicator(DefinitelyProcessingUserGesture);
+    UserGestureIndicator gestureIndicator(DefinitelyProcessingUserGesture, m_frame.document());
 
     // FIXME (bug 68185): this call should be made at another abstraction layer
-    m_frame->loader()->resetMultipleFormSubmissionProtection();
-    
+    m_frame.loader().resetMultipleFormSubmissionProtection();
+
+#if !ENABLE(IOS_TOUCH_EVENTS)
     cancelFakeMouseMoveEvent();
+#endif
     m_mousePressed = true;
     m_capturesDragging = true;
-    setLastKnownMousePosition(mouseEvent);
-    m_mouseDownTimestamp = mouseEvent.timestamp();
+    setLastKnownMousePosition(platformMouseEvent);
+    m_mouseDownTimestamp = platformMouseEvent.timestamp();
 #if ENABLE(DRAG_SUPPORT)
     m_mouseDownMayStartDrag = false;
 #endif
     m_mouseDownMayStartSelect = false;
     m_mouseDownMayStartAutoscroll = false;
-    if (FrameView* view = m_frame->view())
-        m_mouseDownPos = view->windowToContents(mouseEvent.position());
+    if (FrameView* view = m_frame.view())
+        m_mouseDownPos = view->windowToContents(platformMouseEvent.position());
     else {
         invalidateClick();
         return false;
@@ -1539,24 +1638,24 @@ bool EventHandler::handleMousePressEvent(const PlatformMouseEvent& mouseEvent)
     HitTestRequest request(HitTestRequest::Active | HitTestRequest::DisallowShadowContent);
     // Save the document point we generate in case the window coordinate is invalidated by what happens
     // when we dispatch the event.
-    LayoutPoint documentPoint = documentPointForWindowPoint(m_frame, mouseEvent.position());
-    MouseEventWithHitTestResults mev = m_frame->document()->prepareMouseEvent(request, documentPoint, mouseEvent);
+    LayoutPoint documentPoint = documentPointForWindowPoint(m_frame, platformMouseEvent.position());
+    MouseEventWithHitTestResults mouseEvent = m_frame.document()->prepareMouseEvent(request, documentPoint, platformMouseEvent);
 
-    if (!mev.targetNode()) {
+    if (!mouseEvent.targetNode()) {
         invalidateClick();
         return false;
     }
 
-    m_mousePressNode = mev.targetNode();
+    m_mousePressNode = mouseEvent.targetNode();
 
-    RefPtr<Frame> subframe = subframeForHitTestResult(mev);
-    if (subframe && passMousePressEventToSubframe(mev, subframe.get())) {
+    RefPtr<Frame> subframe = subframeForHitTestResult(mouseEvent);
+    if (subframe && passMousePressEventToSubframe(mouseEvent, subframe.get())) {
         // Start capturing future events for this frame.  We only do this if we didn't clear
         // the m_mousePressed flag, which may happen if an AppKit widget entered a modal event loop.
-        m_capturesDragging = subframe->eventHandler()->capturesDragging();
+        m_capturesDragging = subframe->eventHandler().capturesDragging();
         if (m_mousePressed && m_capturesDragging) {
-            m_capturingMouseEventsNode = mev.targetNode();
-            m_eventHandlerWillResetCapturingMouseEventsNode = true;
+            m_capturingMouseEventsElement = subframe->ownerElement();
+            m_eventHandlerWillResetCapturingMouseEventsElement = true;
         }
         invalidateClick();
         return true;
@@ -1565,7 +1664,7 @@ bool EventHandler::handleMousePressEvent(const PlatformMouseEvent& mouseEvent)
 #if ENABLE(PAN_SCROLLING)
     // We store whether pan scrolling is in progress before calling stopAutoscrollTimer()
     // because it will set m_autoscrollType to NoAutoscroll on return.
-    bool isPanScrollInProgress = m_frame->page() && m_frame->page()->mainFrame()->eventHandler()->panScrollInProgress();
+    bool isPanScrollInProgress = m_frame.mainFrame().eventHandler().panScrollInProgress();
     stopAutoscrollTimer();
     if (isPanScrollInProgress) {
         // We invalidate the click when exiting pan scrolling so that we don't inadvertently navigate
@@ -1575,12 +1674,17 @@ bool EventHandler::handleMousePressEvent(const PlatformMouseEvent& mouseEvent)
     }
 #endif
 
-    m_clickCount = mouseEvent.clickCount();
-    m_clickNode = mev.targetNode();
+    m_clickCount = platformMouseEvent.clickCount();
+    m_clickNode = mouseEvent.targetNode();
+
+    if (!m_clickNode) {
+        invalidateClick();
+        return false;
+    }
 
-    if (FrameView* view = m_frame->view()) {
+    if (FrameView* view = m_frame.view()) {
         RenderLayer* layer = m_clickNode->renderer() ? m_clickNode->renderer()->enclosingLayer() : 0;
-        IntPoint p = view->windowToContents(mouseEvent.position());
+        IntPoint p = view->windowToContents(platformMouseEvent.position());
         if (layer && layer->isPointInResizeControl(p)) {
             layer->setInResizeMode(true);
             m_resizeLayer = layer;
@@ -1590,127 +1694,123 @@ bool EventHandler::handleMousePressEvent(const PlatformMouseEvent& mouseEvent)
         }
     }
 
-    m_frame->selection()->setCaretBlinkingSuspended(true);
+    m_frame.selection().setCaretBlinkingSuspended(true);
 
-    bool swallowEvent = !dispatchMouseEvent(eventNames().mousedownEvent, mev.targetNode(), true, m_clickCount, mouseEvent, true);
-    m_capturesDragging = !swallowEvent || mev.scrollbar();
+    bool swallowEvent = !dispatchMouseEvent(eventNames().mousedownEvent, mouseEvent.targetNode(), true, m_clickCount, platformMouseEvent, true);
+    m_capturesDragging = !swallowEvent || mouseEvent.scrollbar();
 
     // If the hit testing originally determined the event was in a scrollbar, refetch the MouseEventWithHitTestResults
     // in case the scrollbar widget was destroyed when the mouse event was handled.
-    if (mev.scrollbar()) {
-        const bool wasLastScrollBar = mev.scrollbar() == m_lastScrollbarUnderMouse.get();
-        HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::Active | HitTestRequest::DisallowShadowContent);
-        mev = m_frame->document()->prepareMouseEvent(request, documentPoint, mouseEvent);
-        if (wasLastScrollBar && mev.scrollbar() != m_lastScrollbarUnderMouse.get())
-            m_lastScrollbarUnderMouse = 0;
+    if (mouseEvent.scrollbar()) {
+        const bool wasLastScrollBar = mouseEvent.scrollbar() == m_lastScrollbarUnderMouse.get();
+        mouseEvent = m_frame.document()->prepareMouseEvent(HitTestRequest(), documentPoint, platformMouseEvent);
+        if (wasLastScrollBar && mouseEvent.scrollbar() != m_lastScrollbarUnderMouse.get())
+            m_lastScrollbarUnderMouse = nullptr;
     }
 
-    if (swallowEvent) {
-        // scrollbars should get events anyway, even disabled controls might be scrollable
-        Scrollbar* scrollbar = mev.scrollbar();
-
-        updateLastScrollbarUnderMouse(scrollbar, true);
-
-        if (scrollbar)
-            passMousePressEventToScrollbar(mev, scrollbar);
-    } else {
+    if (!swallowEvent) {
         // Refetch the event target node if it currently is the shadow node inside an <input> element.
         // If a mouse event handler changes the input element type to one that has a widget associated,
         // we'd like to EventHandler::handleMousePressEvent to pass the event to the widget and thus the
         // event target node can't still be the shadow node.
-        if (mev.targetNode()->isShadowRoot() && isHTMLInputElement(toShadowRoot(mev.targetNode())->host())) {
-            HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::Active | HitTestRequest::DisallowShadowContent);
-            mev = m_frame->document()->prepareMouseEvent(request, documentPoint, mouseEvent);
-        }
-
-        FrameView* view = m_frame->view();
-        Scrollbar* scrollbar = view ? view->scrollbarAtPoint(mouseEvent.position()) : 0;
-        if (!scrollbar)
-            scrollbar = mev.scrollbar();
+        if (is<ShadowRoot>(*mouseEvent.targetNode()) && is<HTMLInputElement>(*downcast<ShadowRoot>(*mouseEvent.targetNode()).host()))
+            mouseEvent = m_frame.document()->prepareMouseEvent(HitTestRequest(), documentPoint, platformMouseEvent);
+    }
 
-        updateLastScrollbarUnderMouse(scrollbar, true);
+    Scrollbar* scrollbar = scrollbarForMouseEvent(mouseEvent, m_frame.view());
+    updateLastScrollbarUnderMouse(scrollbar, true);
 
-        if (scrollbar && passMousePressEventToScrollbar(mev, scrollbar))
+    bool passedToScrollbar = scrollbar && passMousePressEventToScrollbar(mouseEvent, scrollbar);
+    if (!swallowEvent) {
+        if (passedToScrollbar)
             swallowEvent = true;
         else
-            swallowEvent = handleMousePressEvent(mev);
+            swallowEvent = handleMousePressEvent(mouseEvent);
     }
-
     return swallowEvent;
 }
 
 // This method only exists for platforms that don't know how to deliver 
-bool EventHandler::handleMouseDoubleClickEvent(const PlatformMouseEvent& mouseEvent)
+bool EventHandler::handleMouseDoubleClickEvent(const PlatformMouseEvent& platformMouseEvent)
 {
-    RefPtr<FrameView> protector(m_frame->view());
+    RefPtr<FrameView> protector(m_frame.view());
 
-    m_frame->selection()->setCaretBlinkingSuspended(false);
+    m_frame.selection().setCaretBlinkingSuspended(false);
 
-    UserGestureIndicator gestureIndicator(DefinitelyProcessingUserGesture);
+    UserGestureIndicator gestureIndicator(DefinitelyProcessingUserGesture, m_frame.document());
 
     // We get this instead of a second mouse-up 
     m_mousePressed = false;
-    setLastKnownMousePosition(mouseEvent);
+    setLastKnownMousePosition(platformMouseEvent);
 
     HitTestRequest request(HitTestRequest::Active | HitTestRequest::DisallowShadowContent);
-    MouseEventWithHitTestResults mev = prepareMouseEvent(request, mouseEvent);
-    Frame* subframe = subframeForHitTestResult(mev);
-    if (m_eventHandlerWillResetCapturingMouseEventsNode)
-        m_capturingMouseEventsNode = 0;
-    if (subframe && passMousePressEventToSubframe(mev, subframe))
+    MouseEventWithHitTestResults mouseEvent = prepareMouseEvent(request, platformMouseEvent);
+    Frame* subframe = subframeForHitTestResult(mouseEvent);
+    if (m_eventHandlerWillResetCapturingMouseEventsElement)
+        m_capturingMouseEventsElement = nullptr;
+    if (subframe && passMousePressEventToSubframe(mouseEvent, subframe))
         return true;
 
-    m_clickCount = mouseEvent.clickCount();
-    bool swallowMouseUpEvent = !dispatchMouseEvent(eventNames().mouseupEvent, mev.targetNode(), true, m_clickCount, mouseEvent, false);
+    m_clickCount = platformMouseEvent.clickCount();
+    bool swallowMouseUpEvent = !dispatchMouseEvent(eventNames().mouseupEvent, mouseEvent.targetNode(), true, m_clickCount, platformMouseEvent, false);
 
-    bool swallowClickEvent = mouseEvent.button() != RightButton && mev.targetNode() == m_clickNode && !dispatchMouseEvent(eventNames().clickEvent, mev.targetNode(), true, m_clickCount, mouseEvent, true);
+    bool swallowClickEvent = platformMouseEvent.button() != RightButton && mouseEvent.targetNode() == m_clickNode && !dispatchMouseEvent(eventNames().clickEvent, mouseEvent.targetNode(), true, m_clickCount, platformMouseEvent, true);
 
     if (m_lastScrollbarUnderMouse)
-        swallowMouseUpEvent = m_lastScrollbarUnderMouse->mouseUp(mouseEvent);
+        swallowMouseUpEvent = m_lastScrollbarUnderMouse->mouseUp(platformMouseEvent);
 
-    bool swallowMouseReleaseEvent = !swallowMouseUpEvent && handleMouseReleaseEvent(mev);
+    bool swallowMouseReleaseEvent = !swallowMouseUpEvent && handleMouseReleaseEvent(mouseEvent);
 
     invalidateClick();
 
     return swallowMouseUpEvent || swallowClickEvent || swallowMouseReleaseEvent;
 }
 
-static RenderLayer* layerForNode(Node* node)
+static ScrollableArea* enclosingScrollableArea(Node* node)
 {
     if (!node)
-        return 0;
+        return nullptr;
 
-    RenderObject* renderer = node->renderer();
-    if (!renderer)
-        return 0;
+    for (auto element = node; element; element = element->parentOrShadowHostNode()) {
+        if (is<HTMLIFrameElement>(*element) || is<HTMLHtmlElement>(*element) || is<HTMLDocument>(*element))
+            return nullptr;
 
-    RenderLayer* layer = renderer->enclosingLayer();
-    if (!layer)
-        return 0;
+        auto renderer = element->renderer();
+        if (!renderer)
+            continue;
+
+        if (is<RenderListBox>(*renderer))
+            return downcast<RenderListBox>(renderer);
 
-    return layer;
+        return renderer->enclosingLayer();
+    }
+
+    return nullptr;
 }
 
 bool EventHandler::mouseMoved(const PlatformMouseEvent& event)
 {
-    RefPtr<FrameView> protector(m_frame->view());
+    RefPtr<FrameView> protector(m_frame.view());
     MaximumDurationTracker maxDurationTracker(&m_maxMouseMovedDuration);
 
+    if (m_frame.mainFrame().pageOverlayController().handleMouseEvent(event))
+        return true;
+
     HitTestResult hoveredNode = HitTestResult(LayoutPoint());
     bool result = handleMouseMoveEvent(event, &hoveredNode);
 
-    Page* page = m_frame->page();
+    Page* page = m_frame.page();
     if (!page)
         return result;
 
-    if (RenderLayer* layer = layerForNode(hoveredNode.innerNode())) {
-        if (FrameView* frameView = m_frame->view()) {
-            if (frameView->containsScrollableArea(layer))
-                layer->mouseMovedInContentArea();
+    if (auto scrolledArea = enclosingScrollableArea(hoveredNode.innerNode())) {
+        if (FrameView* frameView = m_frame.view()) {
+            if (frameView->containsScrollableArea(scrolledArea))
+                scrolledArea->mouseMovedInContentArea();
         }
     }
 
-    if (FrameView* frameView = m_frame->view())
+    if (FrameView* frameView = m_frame.view())
         frameView->mouseMovedInContentArea();  
 
     hoveredNode.setToNonShadowAncestor();
@@ -1725,46 +1825,43 @@ bool EventHandler::passMouseMovedEventToScrollbars(const PlatformMouseEvent& eve
     return handleMouseMoveEvent(event, &hoveredNode, true);
 }
 
-bool EventHandler::handleMouseMoveEvent(const PlatformMouseEvent& mouseEvent, HitTestResult* hoveredNode, bool onlyUpdateScrollbars)
+bool EventHandler::handleMouseMoveEvent(const PlatformMouseEvent& platformMouseEvent, HitTestResult* hoveredNode, bool onlyUpdateScrollbars)
 {
-    // in Radar 3703768 we saw frequent crashes apparently due to the
-    // part being null here, which seems impossible, so check for nil
-    // but also assert so that we can try to figure this out in debug
-    // builds, if it happens.
-    ASSERT(m_frame);
-    if (!m_frame)
-        return false;
-
 #if ENABLE(TOUCH_EVENTS)
-    bool defaultPrevented = dispatchSyntheticTouchEventIfEnabled(mouseEvent);
+    bool defaultPrevented = dispatchSyntheticTouchEventIfEnabled(platformMouseEvent);
     if (defaultPrevented)
         return true;
 #endif
 
-    RefPtr<FrameView> protector(m_frame->view());
+    RefPtr<FrameView> protector(m_frame.view());
     
-    setLastKnownMousePosition(mouseEvent);
+    setLastKnownMousePosition(platformMouseEvent);
 
     if (m_hoverTimer.isActive())
         m_hoverTimer.stop();
 
+#if ENABLE(CURSOR_SUPPORT)
     m_cursorUpdateTimer.stop();
+#endif
 
+#if !ENABLE(IOS_TOUCH_EVENTS)
     cancelFakeMouseMoveEvent();
+#endif
 
-#if ENABLE(SVG)
     if (m_svgPan) {
-        toSVGDocument(m_frame->document())->updatePan(m_frame->view()->windowToContents(m_lastKnownMousePosition));
+        downcast<SVGDocument>(*m_frame.document()).updatePan(m_frame.view()->windowToContents(m_lastKnownMousePosition));
         return true;
     }
-#endif
 
     if (m_frameSetBeingResized)
-        return !dispatchMouseEvent(eventNames().mousemoveEvent, m_frameSetBeingResized.get(), false, 0, mouseEvent, false);
+        return !dispatchMouseEvent(eventNames().mousemoveEvent, m_frameSetBeingResized.get(), false, 0, platformMouseEvent, false);
 
+    // On iOS, our scrollbars are managed by UIKit.
+#if !PLATFORM(IOS)
     // Send events right to a scrollbar if the mouse is pressed.
     if (m_lastScrollbarUnderMouse && m_mousePressed)
-        return m_lastScrollbarUnderMouse->mouseMoved(mouseEvent);
+        return m_lastScrollbarUnderMouse->mouseMoved(platformMouseEvent);
+#endif
 
     HitTestRequest::HitTestRequestType hitType = HitTestRequest::Move | HitTestRequest::DisallowShadowContent | HitTestRequest::AllowFrameScrollbars;
     if (m_mousePressed)
@@ -1777,50 +1874,58 @@ bool EventHandler::handleMouseMoveEvent(const PlatformMouseEvent& mouseEvent, Hi
         hitType |= HitTestRequest::ReadOnly;
     }
 
-#if ENABLE(TOUCH_EVENTS)
+#if ENABLE(TOUCH_EVENTS) && !ENABLE(IOS_TOUCH_EVENTS)
     // Treat any mouse move events as readonly if the user is currently touching the screen.
     if (m_touchPressed)
         hitType |= HitTestRequest::Active | HitTestRequest::ReadOnly;
 #endif
     HitTestRequest request(hitType);
-    MouseEventWithHitTestResults mev = prepareMouseEvent(request, mouseEvent);
+    MouseEventWithHitTestResults mouseEvent = prepareMouseEvent(request, platformMouseEvent);
     if (hoveredNode)
-        *hoveredNode = mev.hitTestResult();
+        *hoveredNode = mouseEvent.hitTestResult();
 
     if (m_resizeLayer && m_resizeLayer->inResizeMode())
-        m_resizeLayer->resize(mouseEvent, m_offsetFromResizeCorner);
+        m_resizeLayer->resize(platformMouseEvent, m_offsetFromResizeCorner);
     else {
-        Scrollbar* scrollbar = mev.scrollbar();
+        Scrollbar* scrollbar = mouseEvent.scrollbar();
         updateLastScrollbarUnderMouse(scrollbar, !m_mousePressed);
+
+        // On iOS, our scrollbars are managed by UIKit.
+#if !PLATFORM(IOS)
         if (!m_mousePressed && scrollbar)
-            scrollbar->mouseMoved(mouseEvent); // Handle hover effects on platforms that support visual feedback on scrollbar hovering.
-        if (onlyUpdateScrollbars)
+            scrollbar->mouseMoved(platformMouseEvent); // Handle hover effects on platforms that support visual feedback on scrollbar hovering.
+#endif
+        if (onlyUpdateScrollbars) {
+            updateMouseEventTargetNode(mouseEvent.targetNode(), platformMouseEvent, true);
             return true;
+        }
     }
 
     bool swallowEvent = false;
-    RefPtr<Frame> newSubframe = m_capturingMouseEventsNode.get() ? subframeForTargetNode(m_capturingMouseEventsNode.get()) : subframeForHitTestResult(mev);
+    RefPtr<Frame> newSubframe = m_capturingMouseEventsElement.get() ? subframeForTargetNode(m_capturingMouseEventsElement.get()) : subframeForHitTestResult(mouseEvent);
  
     // We want mouseouts to happen first, from the inside out.  First send a move event to the last subframe so that it will fire mouseouts.
-    if (m_lastMouseMoveEventSubframe && m_lastMouseMoveEventSubframe->tree()->isDescendantOf(m_frame) && m_lastMouseMoveEventSubframe != newSubframe)
-        passMouseMoveEventToSubframe(mev, m_lastMouseMoveEventSubframe.get());
+    if (m_lastMouseMoveEventSubframe && m_lastMouseMoveEventSubframe->tree().isDescendantOf(&m_frame) && m_lastMouseMoveEventSubframe != newSubframe)
+        passMouseMoveEventToSubframe(mouseEvent, m_lastMouseMoveEventSubframe.get());
 
     if (newSubframe) {
         // Update over/out state before passing the event to the subframe.
-        updateMouseEventTargetNode(mev.targetNode(), mouseEvent, true);
+        updateMouseEventTargetNode(mouseEvent.targetNode(), platformMouseEvent, true);
         
         // Event dispatch in updateMouseEventTargetNode may have caused the subframe of the target
         // node to be detached from its FrameView, in which case the event should not be passed.
         if (newSubframe->view())
-            swallowEvent |= passMouseMoveEventToSubframe(mev, newSubframe.get(), hoveredNode);
+            swallowEvent |= passMouseMoveEventToSubframe(mouseEvent, newSubframe.get(), hoveredNode);
+#if ENABLE(CURSOR_SUPPORT)
     } else {
-        if (FrameView* view = m_frame->view()) {
-            OptionalCursor optionalCursor = selectCursor(mev.hitTestResult(), mouseEvent.shiftKey());
+        if (FrameView* view = m_frame.view()) {
+            OptionalCursor optionalCursor = selectCursor(mouseEvent.hitTestResult(), platformMouseEvent.shiftKey());
             if (optionalCursor.isCursorChange()) {
                 m_currentMouseCursor = optionalCursor.cursor();
                 view->setCursor(m_currentMouseCursor);
             }
         }
+#endif
     }
     
     m_lastMouseMoveEventSubframe = newSubframe;
@@ -1828,10 +1933,10 @@ bool EventHandler::handleMouseMoveEvent(const PlatformMouseEvent& mouseEvent, Hi
     if (swallowEvent)
         return true;
     
-    swallowEvent = !dispatchMouseEvent(eventNames().mousemoveEvent, mev.targetNode(), false, 0, mouseEvent, true);
+    swallowEvent = !dispatchMouseEvent(eventNames().mousemoveEvent, mouseEvent.targetNode(), false, 0, platformMouseEvent, true);
 #if ENABLE(DRAG_SUPPORT)
     if (!swallowEvent)
-        swallowEvent = handleMouseDraggedEvent(mev);
+        swallowEvent = handleMouseDraggedEvent(mouseEvent);
 #endif // ENABLE(DRAG_SUPPORT)
 
     return swallowEvent;
@@ -1840,102 +1945,116 @@ bool EventHandler::handleMouseMoveEvent(const PlatformMouseEvent& mouseEvent, Hi
 void EventHandler::invalidateClick()
 {
     m_clickCount = 0;
-    m_clickNode = 0;
+    m_clickNode = nullptr;
 }
 
-inline static bool mouseIsReleasedOnPressedElement(Node* targetNode, Node* clickNode)
+bool EventHandler::handleMouseReleaseEvent(const PlatformMouseEvent& platformMouseEvent)
 {
-    if (targetNode == clickNode)
-        return true;
-
-    if (!targetNode)
-        return false;
-
-    ShadowRoot* containingShadowRoot = targetNode->containingShadowRoot();
-    if (!containingShadowRoot)
-        return false;
-
-    // FIXME: When an element in UA ShadowDOM (e.g. inner element in <input>) is clicked,
-    // we assume that the host element is clicked. This is necessary for implementing <input type="range"> etc.
-    // However, we should not check ShadowRoot type basically.
-    // https://bugs.webkit.org/show_bug.cgi?id=108047
-    if (containingShadowRoot->type() != ShadowRoot::UserAgentShadowRoot)
-        return false;
+    RefPtr<FrameView> protector(m_frame.view());
 
-    Node* adjustedTargetNode = targetNode->shadowHost();
-    Node* adjustedClickNode = clickNode ? clickNode->shadowHost() : 0;
-    return adjustedTargetNode == adjustedClickNode;
-}
+    m_frame.selection().setCaretBlinkingSuspended(false);
 
-bool EventHandler::handleMouseReleaseEvent(const PlatformMouseEvent& mouseEvent)
-{
-    RefPtr<FrameView> protector(m_frame->view());
-
-    m_frame->selection()->setCaretBlinkingSuspended(false);
+    if (m_frame.mainFrame().pageOverlayController().handleMouseEvent(platformMouseEvent))
+        return true;
 
 #if ENABLE(TOUCH_EVENTS)
-    bool defaultPrevented = dispatchSyntheticTouchEventIfEnabled(mouseEvent);
+    bool defaultPrevented = dispatchSyntheticTouchEventIfEnabled(platformMouseEvent);
     if (defaultPrevented)
         return true;
 #endif
 
-    UserGestureIndicator gestureIndicator(DefinitelyProcessingUserGesture);
+    UserGestureIndicator gestureIndicator(DefinitelyProcessingUserGesture, m_frame.document());
 
 #if ENABLE(PAN_SCROLLING)
-    m_autoscrollController->handleMouseReleaseEvent(mouseEvent);
+    m_autoscrollController->handleMouseReleaseEvent(platformMouseEvent);
 #endif
 
     m_mousePressed = false;
-    setLastKnownMousePosition(mouseEvent);
+    setLastKnownMousePosition(platformMouseEvent);
 
-#if ENABLE(SVG)
     if (m_svgPan) {
         m_svgPan = false;
-        toSVGDocument(m_frame->document())->updatePan(m_frame->view()->windowToContents(m_lastKnownMousePosition));
+        downcast<SVGDocument>(*m_frame.document()).updatePan(m_frame.view()->windowToContents(m_lastKnownMousePosition));
         return true;
     }
-#endif
 
     if (m_frameSetBeingResized)
-        return !dispatchMouseEvent(eventNames().mouseupEvent, m_frameSetBeingResized.get(), true, m_clickCount, mouseEvent, false);
+        return !dispatchMouseEvent(eventNames().mouseupEvent, m_frameSetBeingResized.get(), true, m_clickCount, platformMouseEvent, false);
+
+    // If an immediate action began or was completed using this series of mouse events, then we should send mouseup to
+    // the DOM and return now so that we don't perform our own default behaviors.
+    if (m_immediateActionStage == ImmediateActionStage::ActionCompleted || m_immediateActionStage == ImmediateActionStage::ActionUpdated || m_immediateActionStage == ImmediateActionStage::ActionCancelledAfterUpdate) {
+        m_immediateActionStage = ImmediateActionStage::None;
+        return !dispatchMouseEvent(eventNames().mouseupEvent, m_lastElementUnderMouse.get(), true, m_clickCount, platformMouseEvent, false);
+    }
+    m_immediateActionStage = ImmediateActionStage::None;
 
     if (m_lastScrollbarUnderMouse) {
         invalidateClick();
-        m_lastScrollbarUnderMouse->mouseUp(mouseEvent);
+        m_lastScrollbarUnderMouse->mouseUp(platformMouseEvent);
         bool cancelable = true;
         bool setUnder = false;
-        return !dispatchMouseEvent(eventNames().mouseupEvent, m_lastNodeUnderMouse.get(), cancelable, m_clickCount, mouseEvent, setUnder);
+        return !dispatchMouseEvent(eventNames().mouseupEvent, m_lastElementUnderMouse.get(), cancelable, m_clickCount, platformMouseEvent, setUnder);
     }
 
     HitTestRequest request(HitTestRequest::Release | HitTestRequest::DisallowShadowContent);
-    MouseEventWithHitTestResults mev = prepareMouseEvent(request, mouseEvent);
-    Frame* subframe = m_capturingMouseEventsNode.get() ? subframeForTargetNode(m_capturingMouseEventsNode.get()) : subframeForHitTestResult(mev);
-    if (m_eventHandlerWillResetCapturingMouseEventsNode)
-        m_capturingMouseEventsNode = 0;
-    if (subframe && passMouseReleaseEventToSubframe(mev, subframe))
+    MouseEventWithHitTestResults mouseEvent = prepareMouseEvent(request, platformMouseEvent);
+    Frame* subframe = m_capturingMouseEventsElement.get() ? subframeForTargetNode(m_capturingMouseEventsElement.get()) : subframeForHitTestResult(mouseEvent);
+    if (m_eventHandlerWillResetCapturingMouseEventsElement)
+        m_capturingMouseEventsElement = nullptr;
+    if (subframe && passMouseReleaseEventToSubframe(mouseEvent, subframe))
         return true;
 
-    bool swallowMouseUpEvent = !dispatchMouseEvent(eventNames().mouseupEvent, mev.targetNode(), true, m_clickCount, mouseEvent, false);
+    bool swallowMouseUpEvent = !dispatchMouseEvent(eventNames().mouseupEvent, mouseEvent.targetNode(), true, m_clickCount, platformMouseEvent, false);
 
-    bool contextMenuEvent = mouseEvent.button() == RightButton;
+    bool contextMenuEvent = platformMouseEvent.button() == RightButton;
 
-    bool swallowClickEvent = m_clickCount > 0 && !contextMenuEvent && mouseIsReleasedOnPressedElement(mev.targetNode(), m_clickNode.get()) && !dispatchMouseEvent(eventNames().clickEvent, mev.targetNode(), true, m_clickCount, mouseEvent, true);
+    Node* targetNode = mouseEvent.targetNode();
+    Node* nodeToClick = (m_clickNode && targetNode) ? commonAncestorCrossingShadowBoundary(*m_clickNode, *targetNode) : nullptr;
+    bool swallowClickEvent = m_clickCount > 0 && !contextMenuEvent && nodeToClick && !dispatchMouseEvent(eventNames().clickEvent, nodeToClick, true, m_clickCount, platformMouseEvent, true);
 
     if (m_resizeLayer) {
         m_resizeLayer->setInResizeMode(false);
-        m_resizeLayer = 0;
+        m_resizeLayer = nullptr;
     }
 
     bool swallowMouseReleaseEvent = false;
     if (!swallowMouseUpEvent)
-        swallowMouseReleaseEvent = handleMouseReleaseEvent(mev);
+        swallowMouseReleaseEvent = handleMouseReleaseEvent(mouseEvent);
 
     invalidateClick();
 
     return swallowMouseUpEvent || swallowClickEvent || swallowMouseReleaseEvent;
 }
 
-bool EventHandler::handlePasteGlobalSelection(const PlatformMouseEvent& mouseEvent)
+#if ENABLE(MOUSE_FORCE_EVENTS)
+bool EventHandler::handleMouseForceEvent(const PlatformMouseEvent& event)
+{
+    RefPtr<FrameView> protector(m_frame.view());
+
+    setLastKnownMousePosition(event);
+
+    HitTestRequest::HitTestRequestType hitType = HitTestRequest::DisallowShadowContent | HitTestRequest::Active;
+
+    HitTestRequest request(hitType);
+    MouseEventWithHitTestResults mouseEvent = prepareMouseEvent(request, event);
+
+    bool swallowedEvent = !dispatchMouseEvent(eventNames().webkitmouseforcechangedEvent, mouseEvent.targetNode(), false, 0, event, false);
+    if (event.type() == PlatformEvent::MouseForceDown)
+        swallowedEvent |= !dispatchMouseEvent(eventNames().webkitmouseforcedownEvent, mouseEvent.targetNode(), false, 0, event, false);
+    if (event.type() == PlatformEvent::MouseForceUp)
+        swallowedEvent |= !dispatchMouseEvent(eventNames().webkitmouseforceupEvent, mouseEvent.targetNode(), false, 0, event, false);
+
+    return swallowedEvent;
+}
+#else
+bool EventHandler::handleMouseForceEvent(const PlatformMouseEvent& )
+{
+    return false;
+}
+#endif // #if ENABLE(MOUSE_FORCE_EVENTS)
+
+bool EventHandler::handlePasteGlobalSelection(const PlatformMouseEvent& platformMouseEvent)
 {
     // If the event was a middle click, attempt to copy global selection in after
     // the newly set caret position.
@@ -1954,110 +2073,136 @@ bool EventHandler::handlePasteGlobalSelection(const PlatformMouseEvent& mouseEve
     // clears the text box. So it's important this happens after the event
     // handlers have been fired.
 #if PLATFORM(GTK)
-    if (mouseEvent.type() != PlatformEvent::MousePressed)
+    if (platformMouseEvent.type() != PlatformEvent::MousePressed)
         return false;
 #else
-    if (mouseEvent.type() != PlatformEvent::MouseReleased)
+    if (platformMouseEvent.type() != PlatformEvent::MouseReleased)
         return false;
 #endif
 
-    if (!m_frame->page())
+    if (!m_frame.page())
         return false;
-    Frame* focusFrame = m_frame->page()->focusController()->focusedOrMainFrame();
+    Frame& focusFrame = m_frame.page()->focusController().focusedOrMainFrame();
     // Do not paste here if the focus was moved somewhere else.
-    if (m_frame == focusFrame && m_frame->editor().client()->supportsGlobalSelection())
-        return m_frame->editor().command(ASCIILiteral("PasteGlobalSelection")).execute();
+    if (&m_frame == &focusFrame && m_frame.editor().client()->supportsGlobalSelection())
+        return m_frame.editor().command(ASCIILiteral("PasteGlobalSelection")).execute();
 
     return false;
 }
 
-
 #if ENABLE(DRAG_SUPPORT)
-bool EventHandler::dispatchDragEvent(const AtomicString& eventType, Node* dragTarget, const PlatformMouseEvent& event, Clipboard* clipboard)
+
+bool EventHandler::dispatchDragEvent(const AtomicString& eventType, Element& dragTarget, const PlatformMouseEvent& event, DataTransfer* dataTransfer)
 {
-    FrameView* view = m_frame->view();
+    FrameView* view = m_frame.view();
 
     // FIXME: We might want to dispatch a dragleave even if the view is gone.
     if (!view)
         return false;
 
-    view->resetDeferredRepaintDelay();
-    RefPtr<MouseEvent> me = MouseEvent::create(eventType,
-        true, true, event.timestamp(), m_frame->document()->defaultView(),
+    view->disableLayerFlushThrottlingTemporarilyForInteraction();
+    Ref<MouseEvent> me = MouseEvent::create(eventType,
+        true, true, event.timestamp(), m_frame.document()->defaultView(),
         0, event.globalPosition().x(), event.globalPosition().y(), event.position().x(), event.position().y(),
 #if ENABLE(POINTER_LOCK)
         event.movementDelta().x(), event.movementDelta().y(),
 #endif
         event.ctrlKey(), event.altKey(), event.shiftKey(), event.metaKey(),
-        0, 0, clipboard);
+        0, 0, event.force(), dataTransfer);
 
-    dragTarget->dispatchEvent(me.get(), IGNORE_EXCEPTION);
+    dragTarget.dispatchEvent(me);
     return me->defaultPrevented();
 }
 
 static bool targetIsFrame(Node* target, Frame*& frame)
 {
-    if (!target)
+    if (!is<HTMLFrameElementBase>(target))
         return false;
 
-    if (!target->hasTagName(frameTag) && !target->hasTagName(iframeTag))
-        return false;
+    frame = downcast<HTMLFrameElementBase>(*target).contentFrame();
+    return true;
+}
 
-    frame = toHTMLFrameElementBase(target)->contentFrame();
+static DragOperation convertDropZoneOperationToDragOperation(const String& dragOperation)
+{
+    if (dragOperation == "copy")
+        return DragOperationCopy;
+    if (dragOperation == "move")
+        return DragOperationMove;
+    if (dragOperation == "link")
+        return DragOperationLink;
+    return DragOperationNone;
+}
 
-    return true;
+static String convertDragOperationToDropZoneOperation(DragOperation operation)
+{
+    switch (operation) {
+    case DragOperationCopy:
+        return ASCIILiteral("copy");
+    case DragOperationMove:
+        return ASCIILiteral("move");
+    case DragOperationLink:
+        return ASCIILiteral("link");
+    default:
+        return ASCIILiteral("copy");
+    }
 }
 
-static bool findDropZone(Node* target, Clipboard* clipboard)
+static bool hasDropZoneType(DataTransfer& dataTransfer, const String& keyword)
 {
-    Element* element = target->isElementNode() ? toElement(target) : target->parentElement();
+    if (keyword.startsWith("file:"))
+        return dataTransfer.hasFileOfType(keyword.substring(5));
+
+    if (keyword.startsWith("string:"))
+        return dataTransfer.hasStringOfType(keyword.substring(7));
+
+    return false;
+}
+
+static bool findDropZone(Node* target, DataTransfer* dataTransfer)
+{
+    ASSERT(target);
+    Element* element = is<Element>(*target) ? downcast<Element>(target) : target->parentElement();
     for (; element; element = element->parentElement()) {
+        SpaceSplitString keywords(element->fastGetAttribute(webkitdropzoneAttr), true);
         bool matched = false;
-        String dropZoneStr = element->fastGetAttribute(webkitdropzoneAttr);
-
-        if (dropZoneStr.isEmpty())
-            continue;
-        
-        dropZoneStr.makeLower();
-        
-        SpaceSplitString keywords(dropZoneStr, false);
-        if (keywords.isNull())
-            continue;
-        
         DragOperation dragOperation = DragOperationNone;
-        for (unsigned int i = 0; i < keywords.size(); i++) {
+        for (unsigned i = 0, size = keywords.size(); i < size; ++i) {
             DragOperation op = convertDropZoneOperationToDragOperation(keywords[i]);
             if (op != DragOperationNone) {
                 if (dragOperation == DragOperationNone)
                     dragOperation = op;
             } else
-                matched = matched || clipboard->hasDropZoneType(keywords[i].string());
-
+                matched = matched || hasDropZoneType(*dataTransfer, keywords[i].string());
             if (matched && dragOperation != DragOperationNone)
                 break;
         }
         if (matched) {
-            clipboard->setDropEffect(convertDragOperationToDropZoneOperation(dragOperation));
+            dataTransfer->setDropEffect(convertDragOperationToDropZoneOperation(dragOperation));
             return true;
         }
     }
     return false;
 }
     
-bool EventHandler::updateDragAndDrop(const PlatformMouseEvent& event, Clipboard* clipboard)
+bool EventHandler::updateDragAndDrop(const PlatformMouseEvent& event, DataTransfer* dataTransfer)
 {
     bool accept = false;
 
-    if (!m_frame->view())
+    if (!m_frame.view())
         return false;
 
     HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::DisallowShadowContent);
-    MouseEventWithHitTestResults mev = prepareMouseEvent(request, event);
+    MouseEventWithHitTestResults mouseEvent = prepareMouseEvent(request, event);
 
-    // Drag events should never go to text nodes (following IE, and proper mouseover/out dispatch)
-    RefPtr<Node> newTarget = mev.targetNode();
-    if (newTarget && newTarget->isTextNode())
-        newTarget = EventPathWalker::parent(newTarget.get());
+    RefPtr<Element> newTarget;
+    if (Node* targetNode = mouseEvent.targetNode()) {
+        // Drag events should never go to non-element nodes (following IE, and proper mouseover/out dispatch)
+        if (!is<Element>(*targetNode))
+            newTarget = targetNode->parentOrShadowHostElement();
+        else
+            newTarget = downcast<Element>(targetNode);
+    }
 
     m_autoscrollController->updateDragAndDrop(newTarget.get(), event.position(), event.timestamp());
 
@@ -2070,23 +2215,23 @@ bool EventHandler::updateDragAndDrop(const PlatformMouseEvent& event, Clipboard*
         Frame* targetFrame;
         if (targetIsFrame(newTarget.get(), targetFrame)) {
             if (targetFrame)
-                accept = targetFrame->eventHandler()->updateDragAndDrop(event, clipboard);
+                accept = targetFrame->eventHandler().updateDragAndDrop(event, dataTransfer);
         } else if (newTarget) {
             // As per section 7.9.4 of the HTML 5 spec., we must always fire a drag event before firing a dragenter, dragleave, or dragover event.
             if (dragState().source && dragState().shouldDispatchEvents) {
                 // for now we don't care if event handler cancels default behavior, since there is none
                 dispatchDragSrcEvent(eventNames().dragEvent, event);
             }
-            accept = dispatchDragEvent(eventNames().dragenterEvent, newTarget.get(), event, clipboard);
+            accept = dispatchDragEvent(eventNames().dragenterEvent, *newTarget, event, dataTransfer);
             if (!accept)
-                accept = findDropZone(newTarget.get(), clipboard);
+                accept = findDropZone(newTarget.get(), dataTransfer);
         }
 
         if (targetIsFrame(m_dragTarget.get(), targetFrame)) {
             if (targetFrame)
-                accept = targetFrame->eventHandler()->updateDragAndDrop(event, clipboard);
+                accept = targetFrame->eventHandler().updateDragAndDrop(event, dataTransfer);
         } else if (m_dragTarget)
-            dispatchDragEvent(eventNames().dragleaveEvent, m_dragTarget.get(), event, clipboard);
+            dispatchDragEvent(eventNames().dragleaveEvent, *m_dragTarget, event, dataTransfer);
 
         if (newTarget) {
             // We do not explicitly call dispatchDragEvent here because it could ultimately result in the appearance that
@@ -2097,47 +2242,46 @@ bool EventHandler::updateDragAndDrop(const PlatformMouseEvent& event, Clipboard*
         Frame* targetFrame;
         if (targetIsFrame(newTarget.get(), targetFrame)) {
             if (targetFrame)
-                accept = targetFrame->eventHandler()->updateDragAndDrop(event, clipboard);
+                accept = targetFrame->eventHandler().updateDragAndDrop(event, dataTransfer);
         } else if (newTarget) {
             // Note, when dealing with sub-frames, we may need to fire only a dragover event as a drag event may have been fired earlier.
             if (!m_shouldOnlyFireDragOverEvent && dragState().source && dragState().shouldDispatchEvents) {
                 // for now we don't care if event handler cancels default behavior, since there is none
                 dispatchDragSrcEvent(eventNames().dragEvent, event);
             }
-            accept = dispatchDragEvent(eventNames().dragoverEvent, newTarget.get(), event, clipboard);
+            accept = dispatchDragEvent(eventNames().dragoverEvent, *newTarget, event, dataTransfer);
             if (!accept)
-                accept = findDropZone(newTarget.get(), clipboard);
+                accept = findDropZone(newTarget.get(), dataTransfer);
             m_shouldOnlyFireDragOverEvent = false;
         }
     }
-    m_dragTarget = newTarget;
-
+    m_dragTarget = newTarget.release();
     return accept;
 }
 
-void EventHandler::cancelDragAndDrop(const PlatformMouseEvent& event, Clipboard* clipboard)
+void EventHandler::cancelDragAndDrop(const PlatformMouseEvent& event, DataTransfer* dataTransfer)
 {
     Frame* targetFrame;
     if (targetIsFrame(m_dragTarget.get(), targetFrame)) {
         if (targetFrame)
-            targetFrame->eventHandler()->cancelDragAndDrop(event, clipboard);
-    } else if (m_dragTarget.get()) {
+            targetFrame->eventHandler().cancelDragAndDrop(event, dataTransfer);
+    } else if (m_dragTarget) {
         if (dragState().source && dragState().shouldDispatchEvents)
             dispatchDragSrcEvent(eventNames().dragEvent, event);
-        dispatchDragEvent(eventNames().dragleaveEvent, m_dragTarget.get(), event, clipboard);
+        dispatchDragEvent(eventNames().dragleaveEvent, *m_dragTarget, event, dataTransfer);
     }
     clearDragState();
 }
 
-bool EventHandler::performDragAndDrop(const PlatformMouseEvent& event, Clipboard* clipboard)
+bool EventHandler::performDragAndDrop(const PlatformMouseEvent& event, DataTransfer* dataTransfer)
 {
     Frame* targetFrame;
     bool preventedDefault = false;
     if (targetIsFrame(m_dragTarget.get(), targetFrame)) {
         if (targetFrame)
-            preventedDefault = targetFrame->eventHandler()->performDragAndDrop(event, clipboard);
-    } else if (m_dragTarget.get())
-        preventedDefault = dispatchDragEvent(eventNames().dropEvent, m_dragTarget.get(), event, clipboard);
+            preventedDefault = targetFrame->eventHandler().performDragAndDrop(event, dataTransfer);
+    } else if (m_dragTarget)
+        preventedDefault = dispatchDragEvent(eventNames().dropEvent, *m_dragTarget, event, dataTransfer);
     clearDragState();
     return preventedDefault;
 }
@@ -2145,188 +2289,197 @@ bool EventHandler::performDragAndDrop(const PlatformMouseEvent& event, Clipboard
 void EventHandler::clearDragState()
 {
     stopAutoscrollTimer();
-    m_dragTarget = 0;
-    m_capturingMouseEventsNode = 0;
+    m_dragTarget = nullptr;
+    m_capturingMouseEventsElement = nullptr;
     m_shouldOnlyFireDragOverEvent = false;
-#if PLATFORM(MAC)
+#if PLATFORM(COCOA)
     m_sendingEventToSubview = false;
 #endif
 }
 #endif // ENABLE(DRAG_SUPPORT)
 
-void EventHandler::setCapturingMouseEventsNode(PassRefPtr<Node> n)
+void EventHandler::setCapturingMouseEventsElement(PassRefPtr<Element> element)
 {
-    m_capturingMouseEventsNode = n;
-    m_eventHandlerWillResetCapturingMouseEventsNode = false;
+    m_capturingMouseEventsElement = element;
+    m_eventHandlerWillResetCapturingMouseEventsElement = false;
 }
 
-MouseEventWithHitTestResults EventHandler::prepareMouseEvent(const HitTestRequest& request, const PlatformMouseEvent& mev)
+MouseEventWithHitTestResults EventHandler::prepareMouseEvent(const HitTestRequest& request, const PlatformMouseEvent& mouseEvent)
 {
-    ASSERT(m_frame);
-    ASSERT(m_frame->document());
-    
-    return m_frame->document()->prepareMouseEvent(request, documentPointForWindowPoint(m_frame, mev.position()), mev);
+    ASSERT(m_frame.document());
+    return m_frame.document()->prepareMouseEvent(request, documentPointForWindowPoint(m_frame, mouseEvent.position()), mouseEvent);
 }
 
-#if ENABLE(SVG)
-static inline SVGElementInstance* instanceAssociatedWithShadowTreeElement(Node* referenceNode)
+static RenderElement* nearestCommonHoverAncestor(RenderElement* obj1, RenderElement* obj2)
 {
-    if (!referenceNode || !referenceNode->isSVGElement())
-        return 0;
+    if (!obj1 || !obj2)
+        return nullptr;
 
-    ShadowRoot* shadowRoot = referenceNode->containingShadowRoot();
-    if (!shadowRoot)
-        return 0;
+    for (RenderElement* currObj1 = obj1; currObj1; currObj1 = currObj1->hoverAncestor()) {
+        for (RenderElement* currObj2 = obj2; currObj2; currObj2 = currObj2->hoverAncestor()) {
+            if (currObj1 == currObj2)
+                return currObj1;
+        }
+    }
 
-    Element* shadowTreeParentElement = shadowRoot->host();
-    if (!shadowTreeParentElement || !shadowTreeParentElement->hasTagName(useTag))
-        return 0;
+    return nullptr;
+}
 
-    return toSVGUseElement(shadowTreeParentElement)->instanceForShadowTreeElement(referenceNode);
+static bool hierarchyHasCapturingEventListeners(Element* element, const AtomicString& eventName)
+{
+    for (ContainerNode* curr = element; curr; curr = curr->parentOrShadowHostNode()) {
+        if (curr->hasCapturingEventListeners(eventName))
+            return true;
+    }
+    return false;
 }
-#endif
 
-void EventHandler::updateMouseEventTargetNode(Node* targetNode, const PlatformMouseEvent& mouseEvent, bool fireMouseOverOut)
+void EventHandler::updateMouseEventTargetNode(Node* targetNode, const PlatformMouseEvent& platformMouseEvent, bool fireMouseOverOut)
 {
-    Node* result = targetNode;
+    Element* targetElement = nullptr;
     
-    // If we're capturing, we always go right to that node.
-    if (m_capturingMouseEventsNode)
-        result = m_capturingMouseEventsNode.get();
-    else {
-        // If the target node is a text node, dispatch on the parent node - rdar://4196646
-        if (result && result->isTextNode())
-            result = EventPathWalker::parent(result);
+    // If we're capturing, we always go right to that element.
+    if (m_capturingMouseEventsElement)
+        targetElement = m_capturingMouseEventsElement.get();
+    else if (targetNode) {
+        // If the target node is a non-element, dispatch on the parent. <rdar://problem/4196646>
+        if (!is<Element>(*targetNode))
+            targetElement = targetNode->parentOrShadowHostElement();
+        else
+            targetElement = downcast<Element>(targetNode);
     }
-    m_nodeUnderMouse = result;
-#if ENABLE(SVG)
-    m_instanceUnderMouse = instanceAssociatedWithShadowTreeElement(result);
-
-    // <use> shadow tree elements may have been recloned, update node under mouse in any case
-    if (m_lastInstanceUnderMouse) {
-        SVGElement* lastCorrespondingElement = m_lastInstanceUnderMouse->correspondingElement();
-        SVGElement* lastCorrespondingUseElement = m_lastInstanceUnderMouse->correspondingUseElement();
-
-        if (lastCorrespondingElement && lastCorrespondingUseElement) {
-            HashSet<SVGElementInstance*> instances = lastCorrespondingElement->instancesForElement();
 
-            // Locate the recloned shadow tree element for our corresponding instance
-            HashSet<SVGElementInstance*>::iterator end = instances.end();
-            for (HashSet<SVGElementInstance*>::iterator it = instances.begin(); it != end; ++it) {
-                SVGElementInstance* instance = (*it);
-                ASSERT(instance->correspondingElement() == lastCorrespondingElement);
-
-                if (instance == m_lastInstanceUnderMouse)
-                    continue;
-
-                if (instance->correspondingUseElement() != lastCorrespondingUseElement)
-                    continue;
-
-                SVGElement* shadowTreeElement = instance->shadowTreeElement();
-                if (!shadowTreeElement->inDocument() || m_lastNodeUnderMouse == shadowTreeElement)
-                    continue;
-
-                m_lastNodeUnderMouse = shadowTreeElement;
-                m_lastInstanceUnderMouse = instance;
-                break;
-            }
-        }
-    }
-#endif
+    m_elementUnderMouse = targetElement;
 
     // Fire mouseout/mouseover if the mouse has shifted to a different node.
     if (fireMouseOverOut) {
-        RenderLayer* layerForLastNode = layerForNode(m_lastNodeUnderMouse.get());
-        RenderLayer* layerForNodeUnderMouse = layerForNode(m_nodeUnderMouse.get());
-        Page* page = m_frame->page();
+        auto scrollableAreaForLastNode = enclosingScrollableArea(m_lastElementUnderMouse.get());
+        auto scrollableAreaForNodeUnderMouse = enclosingScrollableArea(m_elementUnderMouse.get());
+        Page* page = m_frame.page();
 
-        if (m_lastNodeUnderMouse && (!m_nodeUnderMouse || m_nodeUnderMouse->document() != m_frame->document())) {
+        if (m_lastElementUnderMouse && (!m_elementUnderMouse || &m_elementUnderMouse->document() != m_frame.document())) {
             // The mouse has moved between frames.
-            if (Frame* frame = m_lastNodeUnderMouse->document()->frame()) {
+            if (Frame* frame = m_lastElementUnderMouse->document().frame()) {
                 if (FrameView* frameView = frame->view())
                     frameView->mouseExitedContentArea();
             }
-        } else if (page && (layerForLastNode && (!layerForNodeUnderMouse || layerForNodeUnderMouse != layerForLastNode))) {
+        } else if (page && (scrollableAreaForLastNode && (!scrollableAreaForNodeUnderMouse || scrollableAreaForNodeUnderMouse != scrollableAreaForLastNode))) {
             // The mouse has moved between layers.
-            if (Frame* frame = m_lastNodeUnderMouse->document()->frame()) {
+            if (Frame* frame = m_lastElementUnderMouse->document().frame()) {
                 if (FrameView* frameView = frame->view()) {
-                    if (frameView->containsScrollableArea(layerForLastNode))
-                        layerForLastNode->mouseExitedContentArea();
+                    if (frameView->containsScrollableArea(scrollableAreaForLastNode))
+                        scrollableAreaForLastNode->mouseExitedContentArea();
                 }
             }
         }
 
-        if (m_nodeUnderMouse && (!m_lastNodeUnderMouse || m_lastNodeUnderMouse->document() != m_frame->document())) {
+        if (m_elementUnderMouse && (!m_lastElementUnderMouse || &m_lastElementUnderMouse->document() != m_frame.document())) {
             // The mouse has moved between frames.
-            if (Frame* frame = m_nodeUnderMouse->document()->frame()) {
+            if (Frame* frame = m_elementUnderMouse->document().frame()) {
                 if (FrameView* frameView = frame->view())
                     frameView->mouseEnteredContentArea();
             }
-        } else if (page && (layerForNodeUnderMouse && (!layerForLastNode || layerForNodeUnderMouse != layerForLastNode))) {
+        } else if (page && (scrollableAreaForNodeUnderMouse && (!scrollableAreaForLastNode || scrollableAreaForNodeUnderMouse != scrollableAreaForLastNode))) {
             // The mouse has moved between layers.
-            if (Frame* frame = m_nodeUnderMouse->document()->frame()) {
+            if (Frame* frame = m_elementUnderMouse->document().frame()) {
                 if (FrameView* frameView = frame->view()) {
-                    if (frameView->containsScrollableArea(layerForNodeUnderMouse))
-                        layerForNodeUnderMouse->mouseEnteredContentArea();
+                    if (frameView->containsScrollableArea(scrollableAreaForNodeUnderMouse))
+                        scrollableAreaForNodeUnderMouse->mouseEnteredContentArea();
                 }
             }
         }
 
-        if (m_lastNodeUnderMouse && m_lastNodeUnderMouse->document() != m_frame->document()) {
-            m_lastNodeUnderMouse = 0;
-            m_lastScrollbarUnderMouse = 0;
-#if ENABLE(SVG)
-            m_lastInstanceUnderMouse = 0;
-#endif
+        if (m_lastElementUnderMouse && &m_lastElementUnderMouse->document() != m_frame.document()) {
+            m_lastElementUnderMouse = nullptr;
+            m_lastScrollbarUnderMouse = nullptr;
         }
 
-        if (m_lastNodeUnderMouse != m_nodeUnderMouse) {
-            // send mouseout event to the old node
-            if (m_lastNodeUnderMouse)
-                m_lastNodeUnderMouse->dispatchMouseEvent(mouseEvent, eventNames().mouseoutEvent, 0, m_nodeUnderMouse.get());
-            // send mouseover event to the new node
-            if (m_nodeUnderMouse)
-                m_nodeUnderMouse->dispatchMouseEvent(mouseEvent, eventNames().mouseoverEvent, 0, m_lastNodeUnderMouse.get());
+        if (m_lastElementUnderMouse != m_elementUnderMouse) {
+            // mouseenter and mouseleave events are only dispatched if there is a capturing eventhandler on an ancestor
+            // or a normal eventhandler on the element itself (they don't bubble).
+            // This optimization is necessary since these events can cause O(n^2) capturing event-handler checks.
+            bool hasCapturingMouseEnterListener = hierarchyHasCapturingEventListeners(m_elementUnderMouse.get(), eventNames().mouseenterEvent);
+            bool hasCapturingMouseLeaveListener = hierarchyHasCapturingEventListeners(m_lastElementUnderMouse.get(), eventNames().mouseleaveEvent);
+
+            RenderElement* oldHoverRenderer = m_lastElementUnderMouse ? m_lastElementUnderMouse->renderer() : nullptr;
+            RenderElement* newHoverRenderer = m_elementUnderMouse ? m_elementUnderMouse->renderer() : nullptr;
+            RenderElement* ancestor = nearestCommonHoverAncestor(oldHoverRenderer, newHoverRenderer);
+
+            Vector<Ref<Element>, 32> leftElementsChain;
+            if (oldHoverRenderer) {
+                for (RenderElement* curr = oldHoverRenderer; curr && curr != ancestor; curr = curr->hoverAncestor()) {
+                    if (Element* element = curr->element())
+                        leftElementsChain.append(*element);
+                }
+            } else {
+                // If the old hovered element is not null but it's renderer is, it was probably detached.
+                // In this case, the old hovered element (and its ancestors) must be updated, to ensure it's normal style is re-applied.
+                for (Element* element = m_lastElementUnderMouse.get(); element; element = element->parentElement())
+                    leftElementsChain.append(*element);
+            }
+
+            Vector<Ref<Element>, 32> enteredElementsChain;
+            const Element* ancestorElement = ancestor ? ancestor->element() : nullptr;
+            for (RenderElement* curr = newHoverRenderer; curr; curr = curr->hoverAncestor()) {
+                if (Element *element = curr->element()) {
+                    if (element == ancestorElement)
+                        break;
+                    enteredElementsChain.append(*element);
+                }
+            }
+
+            // Send mouseout event to the old node.
+            if (m_lastElementUnderMouse)
+                m_lastElementUnderMouse->dispatchMouseEvent(platformMouseEvent, eventNames().mouseoutEvent, 0, m_elementUnderMouse.get());
+
+            // Send mouseleave to the node hierarchy no longer under the mouse.
+            for (auto& chain : leftElementsChain) {
+                if (hasCapturingMouseLeaveListener || chain->hasEventListeners(eventNames().mouseleaveEvent))
+                    chain->dispatchMouseEvent(platformMouseEvent, eventNames().mouseleaveEvent, 0, m_elementUnderMouse.get());
+            }
+
+            // Send mouseover event to the new node.
+            if (m_elementUnderMouse)
+                m_elementUnderMouse->dispatchMouseEvent(platformMouseEvent, eventNames().mouseoverEvent, 0, m_lastElementUnderMouse.get());
+
+            // Send mouseleave event to the nodes hierarchy under the mouse.
+            for (auto& chain : enteredElementsChain) {
+                if (hasCapturingMouseEnterListener || chain->hasEventListeners(eventNames().mouseenterEvent))
+                    chain->dispatchMouseEvent(platformMouseEvent, eventNames().mouseenterEvent, 0, m_lastElementUnderMouse.get());
+            }
         }
-        m_lastNodeUnderMouse = m_nodeUnderMouse;
-#if ENABLE(SVG)
-        m_lastInstanceUnderMouse = instanceAssociatedWithShadowTreeElement(m_nodeUnderMouse.get());
-#endif
+        m_lastElementUnderMouse = m_elementUnderMouse;
     }
 }
 
-bool EventHandler::dispatchMouseEvent(const AtomicString& eventType, Node* targetNode, bool /*cancelable*/, int clickCount, const PlatformMouseEvent& mouseEvent, bool setUnder)
+bool EventHandler::dispatchMouseEvent(const AtomicString& eventType, Node* targetNode, bool /*cancelable*/, int clickCount, const PlatformMouseEvent& platformMouseEvent, bool setUnder)
 {
-    if (FrameView* view = m_frame->view())
-        view->resetDeferredRepaintDelay();
+    if (FrameView* view = m_frame.view())
+        view->disableLayerFlushThrottlingTemporarilyForInteraction();
 
-    updateMouseEventTargetNode(targetNode, mouseEvent, setUnder);
+    updateMouseEventTargetNode(targetNode, platformMouseEvent, setUnder);
 
     bool swallowEvent = false;
 
-    if (m_nodeUnderMouse)
-        swallowEvent = !(m_nodeUnderMouse->dispatchMouseEvent(mouseEvent, eventType, clickCount));
+    if (m_elementUnderMouse)
+        swallowEvent = !(m_elementUnderMouse->dispatchMouseEvent(platformMouseEvent, eventType, clickCount));
 
     if (!swallowEvent && eventType == eventNames().mousedownEvent) {
 
         // If clicking on a frame scrollbar, do not mess up with content focus.
-        if (FrameView* view = m_frame->view()) {
-            if (view->scrollbarAtPoint(mouseEvent.position()))
+        if (FrameView* view = m_frame.view()) {
+            if (view->scrollbarAtPoint(platformMouseEvent.position()))
                 return true;
         }
 
         // The layout needs to be up to date to determine if an element is focusable.
-        m_frame->document()->updateLayoutIgnorePendingStylesheets();
+        m_frame.document()->updateLayoutIgnorePendingStylesheets();
 
         // Blur current focus node when a link/button is clicked; this
         // is expected by some sites that rely on onChange handlers running
         // from form fields before the button click is processed.
 
-        Element* element;
-        if (m_nodeUnderMouse)
-            element = m_nodeUnderMouse->isElementNode() ? toElement(m_nodeUnderMouse.get()) : m_nodeUnderMouse->parentOrShadowHostElement();
-        else
-            element = 0;
+        Element* element = m_elementUnderMouse.get();
 
         // Walk up the DOM tree to search for an element to focus.
         while (element) {
@@ -2335,9 +2488,9 @@ bool EventHandler::dispatchMouseEvent(const AtomicString& eventType, Node* targe
                 // node on mouse down if it's selected and inside a focused node. It will be
                 // focused if the user does a mouseup over it, however, because the mouseup
                 // will set a selection inside it, which will call setFocuseNodeIfNeeded.
-                if (m_frame->selection()->isRange()
-                    && m_frame->selection()->toNormalizedRange()->compareNode(element, IGNORE_EXCEPTION) == Range::NODE_INSIDE
-                    && element->isDescendantOf(m_frame->document()->focusedElement()))
+                if (m_frame.selection().isRange()
+                    && m_frame.selection().toNormalizedRange()->compareNode(element, IGNORE_EXCEPTION) == Range::NODE_INSIDE
+                    && element->isDescendantOf(m_frame.document()->focusedElement()))
                     return true;
                     
                 break;
@@ -2346,17 +2499,17 @@ bool EventHandler::dispatchMouseEvent(const AtomicString& eventType, Node* targe
         }
 
         // Only change the focus when clicking scrollbars if it can transfered to a mouse focusable node.
-        if ((!element || !element->isMouseFocusable()) && isInsideScrollbar(mouseEvent.position()))
+        if ((!element || !element->isMouseFocusable()) && isInsideScrollbar(platformMouseEvent.position()))
             return false;
 
         // If focus shift is blocked, we eat the event.  Note we should never clear swallowEvent
         // if the page already set it (e.g., by canceling default behavior).
-        if (Page* page = m_frame->page()) {
+        if (Page* page = m_frame.page()) {
             if (element && element->isMouseFocusable()) {
-                if (!page->focusController()->setFocusedElement(element, m_frame))
+                if (!page->focusController().setFocusedElement(element, &m_frame))
                     swallowEvent = true;
             } else if (!element || !element->focused()) {
-                if (!page->focusController()->setFocusedElement(0, m_frame))
+                if (!page->focusController().setFocusedElement(0, &m_frame))
                     swallowEvent = true;
             }
         }
@@ -2367,7 +2520,7 @@ bool EventHandler::dispatchMouseEvent(const AtomicString& eventType, Node* targe
 
 bool EventHandler::isInsideScrollbar(const IntPoint& windowPoint) const
 {
-    if (RenderView* renderView = m_frame->contentRenderer()) {
+    if (RenderView* renderView = m_frame.contentRenderer()) {
         HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::DisallowShadowContent);
         HitTestResult result(windowPoint);
         renderView->hitTest(request, result);
@@ -2378,546 +2531,203 @@ bool EventHandler::isInsideScrollbar(const IntPoint& windowPoint) const
 }
 
 #if !PLATFORM(GTK)
+
 bool EventHandler::shouldTurnVerticalTicksIntoHorizontal(const HitTestResult&, const PlatformWheelEvent&) const
 {
     return false;
 }
-#endif
-
-bool EventHandler::handleWheelEvent(const PlatformWheelEvent& e)
-{
-    Document* doc = m_frame->document();
-
-    RenderObject* docRenderer = doc->renderer();
-    if (!docRenderer)
-        return false;
-    
-    RefPtr<FrameView> protector(m_frame->view());
-
-    FrameView* view = m_frame->view();
-    if (!view)
-        return false;
-
-    m_isHandlingWheelEvent = true;
-    setFrameWasScrolledByUser();
-    LayoutPoint vPoint = view->windowToContents(e.position());
-
-    HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::DisallowShadowContent);
-    HitTestResult result(vPoint);
-    doc->renderView()->hitTest(request, result);
-
-    bool useLatchedWheelEventNode = e.useLatchedEventNode();
-
-    // FIXME: Is the following code different from just calling innerElement?
-    Node* node = result.innerNode();
-    // Wheel events should not dispatch to text nodes.
-    if (node && node->isTextNode())
-        node = EventPathWalker::parent(node);
-
-    bool isOverWidget;
-    if (useLatchedWheelEventNode) {
-        if (!m_latchedWheelEventNode) {
-            m_latchedWheelEventNode = node;
-            m_widgetIsLatched = result.isOverWidget();
-        } else
-            node = m_latchedWheelEventNode.get();
-
-        isOverWidget = m_widgetIsLatched;
-    } else {
-        if (m_latchedWheelEventNode)
-            m_latchedWheelEventNode = 0;
-        if (m_previousWheelScrolledNode)
-            m_previousWheelScrolledNode = 0;
-
-        isOverWidget = result.isOverWidget();
-    }
-
-    // FIXME: It should not be necessary to do this mutation here.
-    // Instead, the handlers should know convert vertical scrolls
-    // appropriately.
-    PlatformWheelEvent event = e;
-    if (m_baseEventType == PlatformEvent::NoType && shouldTurnVerticalTicksIntoHorizontal(result, e))
-        event = event.copyTurningVerticalTicksIntoHorizontalTicks();
-
-    if (node) {
-        // Figure out which view to send the event to.
-        RenderObject* target = node->renderer();
-        
-        if (isOverWidget && target && target->isWidget()) {
-            Widget* widget = toRenderWidget(target)->widget();
-            if (widget && passWheelEventToWidget(e, widget)) {
-                m_isHandlingWheelEvent = false;
-                return true;
-            }
-        }
-
-        if (node && !node->dispatchWheelEvent(event)) {
-            m_isHandlingWheelEvent = false;
-            return true;
-        }
-    }
-
 
-    // We do another check on the frame view because the event handler can run JS which results in the frame getting destroyed.
-    view = m_frame->view();
-    bool didHandleEvent = view ? view->wheelEvent(event) : false;
-    m_isHandlingWheelEvent = false;
-    return didHandleEvent;
-}
+#endif
 
-void EventHandler::defaultWheelEventHandler(Node* startNode, WheelEvent* wheelEvent)
-{
-    if (!startNode || !wheelEvent)
-        return;
-    
-    Node* stopNode = m_previousWheelScrolledNode.get();
-    ScrollGranularity granularity = wheelGranularityToScrollGranularity(wheelEvent->deltaMode());
-    
-    // Break up into two scrolls if we need to.  Diagonal movement on 
-    // a MacBook pro is an example of a 2-dimensional mouse wheel event (where both deltaX and deltaY can be set).
-    if (scrollNode(wheelEvent->rawDeltaX(), granularity, ScrollLeft, ScrollRight, startNode, &stopNode))
-        wheelEvent->setDefaultHandled();
-    
-    if (scrollNode(wheelEvent->rawDeltaY(), granularity, ScrollUp, ScrollDown, startNode, &stopNode))
-        wheelEvent->setDefaultHandled();
-    
-    if (!m_latchedWheelEventNode)
-        m_previousWheelScrolledNode = stopNode;
-}
+#if !PLATFORM(MAC)
 
-#if ENABLE(GESTURE_EVENTS)
-bool EventHandler::handleGestureTapDown()
+void EventHandler::platformPrepareForWheelEvents(const PlatformWheelEvent&, const HitTestResult&, RefPtr<Element>&, RefPtr<ContainerNode>&, ScrollableArea*&, bool&)
 {
-    FrameView* view = m_frame->view();
-    if (!view)
-        return false;
-    if (ScrollAnimator* scrollAnimator = view->existingScrollAnimator())
-        scrollAnimator->cancelAnimations();
-    const FrameView::ScrollableAreaSet* areas = view->scrollableAreas();
-    if (!areas)
-        return false;
-    for (FrameView::ScrollableAreaSet::const_iterator it = areas->begin(); it != areas->end(); ++it) {
-        ScrollableArea* sa = *it;
-        ScrollAnimator* animator = sa->scrollAnimator();
-        if (animator)
-            animator->cancelAnimations();
-    }
-    return false;
 }
 
-bool EventHandler::handleGestureEvent(const PlatformGestureEvent& gestureEvent)
+void EventHandler::platformRecordWheelEvent(const PlatformWheelEvent& event)
 {
-    Node* eventTarget = 0;
-    Scrollbar* scrollbar = 0;
-    if (gestureEvent.type() == PlatformEvent::GestureScrollEnd
-        || gestureEvent.type() == PlatformEvent::GestureScrollUpdate
-        || gestureEvent.type() == PlatformEvent::GestureScrollUpdateWithoutPropagation) {
-        scrollbar = m_scrollbarHandlingScrollGesture.get();
-        eventTarget = m_scrollGestureHandlingNode.get();
-    }
-
-    IntPoint adjustedPoint = gestureEvent.position();
-    HitTestRequest::HitTestRequestType hitType = HitTestRequest::TouchEvent;
-    if (gestureEvent.type() == PlatformEvent::GestureTapDown) {
-#if ENABLE(TOUCH_ADJUSTMENT)
-        adjustGesturePosition(gestureEvent, adjustedPoint);
-#endif
-        hitType |= HitTestRequest::Active;
-    } else if (gestureEvent.type() == PlatformEvent::GestureTapDownCancel)
-        hitType |= HitTestRequest::Release;
-    else if (gestureEvent.type() == PlatformEvent::GestureTap) {
-        // The mouseup event synthesized for this gesture will clear the active state of the
-        // targeted node, so performing a ReadOnly hit test here is fine.
-        hitType |= HitTestRequest::ReadOnly;
-    }
-    else
-        hitType |= HitTestRequest::Active | HitTestRequest::ReadOnly;
-
-    if (!shouldGesturesTriggerActive())
-        hitType |= HitTestRequest::ReadOnly;
-
-    if ((!scrollbar && !eventTarget) || !(hitType & HitTestRequest::ReadOnly)) {
-        IntPoint hitTestPoint = m_frame->view()->windowToContents(adjustedPoint);
-        HitTestResult result = hitTestResultAtPoint(hitTestPoint, hitType | HitTestRequest::AllowFrameScrollbars);
-        eventTarget = result.targetNode();
-        if (!scrollbar)
-            scrollbar = result.scrollbar();
-    }
-
-    if (scrollbar) {
-        bool eventSwallowed = scrollbar->gestureEvent(gestureEvent);
-        if (gestureEvent.type() == PlatformEvent::GestureScrollBegin && eventSwallowed)
-            m_scrollbarHandlingScrollGesture = scrollbar;
-        else if (gestureEvent.type() == PlatformEvent::GestureScrollEnd || !eventSwallowed)
-            m_scrollbarHandlingScrollGesture = 0;
-
-        if (eventSwallowed)
-            return true;
-    }
-
-    if (eventTarget) {
-        bool eventSwallowed = eventTarget->dispatchGestureEvent(gestureEvent);
-        if (gestureEvent.type() == PlatformEvent::GestureScrollBegin || gestureEvent.type() == PlatformEvent::GestureScrollEnd) {
-            if (eventSwallowed)
-                m_scrollGestureHandlingNode = eventTarget;
-        }
-
-        if (eventSwallowed)
-            return true;
-    }
-
-    // FIXME: A more general scroll system (https://bugs.webkit.org/show_bug.cgi?id=80596) will
-    // eliminate the need for this.
-    TemporaryChange<PlatformEvent::Type> baseEventType(m_baseEventType, gestureEvent.type());
-
-    switch (gestureEvent.type()) {
-    case PlatformEvent::GestureScrollBegin:
-        return handleGestureScrollBegin(gestureEvent);
-    case PlatformEvent::GestureScrollUpdate:
-    case PlatformEvent::GestureScrollUpdateWithoutPropagation:
-        return handleGestureScrollUpdate(gestureEvent);
-    case PlatformEvent::GestureScrollEnd:
-        clearGestureScrollNodes(); 
-        return true;
-    case PlatformEvent::GestureTap:
-        return handleGestureTap(gestureEvent);
-    case PlatformEvent::GestureTapDown:
-        return handleGestureTapDown();
-    case PlatformEvent::GestureLongPress:
-        return handleGestureLongPress(gestureEvent);
-    case PlatformEvent::GestureLongTap:
-        return handleGestureLongTap(gestureEvent);
-    case PlatformEvent::GestureTwoFingerTap:
-        return handleGestureTwoFingerTap(gestureEvent);
-    case PlatformEvent::GestureTapDownCancel:
-        break;
-    default:
-        ASSERT_NOT_REACHED();
-    }
-
-    return false;
+    m_frame.mainFrame().wheelEventDeltaFilter()->updateFromDelta(FloatSize(event.deltaX(), event.deltaY()));
 }
 
-bool EventHandler::handleGestureTap(const PlatformGestureEvent& gestureEvent)
+bool EventHandler::platformCompleteWheelEvent(const PlatformWheelEvent& event, ContainerNode*, ScrollableArea*)
 {
-    // FIXME: Refactor this code to not hit test multiple times. We use the adjusted position to ensure that the correct node is targeted by the later redundant hit tests.
-    IntPoint adjustedPoint = gestureEvent.position();
-#if ENABLE(TOUCH_ADJUSTMENT)
-    adjustGesturePosition(gestureEvent, adjustedPoint);
-#endif
-
-    PlatformMouseEvent fakeMouseMove(adjustedPoint, gestureEvent.globalPosition(),
-        NoButton, PlatformEvent::MouseMoved, /* clickCount */ 0,
-        gestureEvent.shiftKey(), gestureEvent.ctrlKey(), gestureEvent.altKey(), gestureEvent.metaKey(), gestureEvent.timestamp());
-    mouseMoved(fakeMouseMove);
-
-    int tapCount = 1;
-    // FIXME: deletaX is overloaded to mean different things for different gestures.
-    // http://wkb.ug/93123
-    if (gestureEvent.deltaX() > 0)
-        tapCount = static_cast<int>(gestureEvent.deltaX());
-
-    bool defaultPrevented = false;
-    PlatformMouseEvent fakeMouseDown(adjustedPoint, gestureEvent.globalPosition(),
-        LeftButton, PlatformEvent::MousePressed, tapCount,
-        gestureEvent.shiftKey(), gestureEvent.ctrlKey(), gestureEvent.altKey(), gestureEvent.metaKey(), gestureEvent.timestamp());
-    defaultPrevented |= handleMousePressEvent(fakeMouseDown);
-
-    PlatformMouseEvent fakeMouseUp(adjustedPoint, gestureEvent.globalPosition(),
-        LeftButton, PlatformEvent::MouseReleased, tapCount,
-        gestureEvent.shiftKey(), gestureEvent.ctrlKey(), gestureEvent.altKey(), gestureEvent.metaKey(), gestureEvent.timestamp());
-    defaultPrevented |= handleMouseReleaseEvent(fakeMouseUp);
-
-    return defaultPrevented;
+    // We do another check on the frame view because the event handler can run JS which results in the frame getting destroyed.
+    FrameView* view = m_frame.view();
+    
+    bool didHandleEvent = view ? view->wheelEvent(event) : false;
+    m_isHandlingWheelEvent = false;
+    return didHandleEvent;
 }
 
-bool EventHandler::handleGestureLongPress(const PlatformGestureEvent& gestureEvent)
+bool EventHandler::platformCompletePlatformWidgetWheelEvent(const PlatformWheelEvent&, const Widget&, ContainerNode*)
 {
-#if ENABLE(DRAG_SUPPORT)
-    if (m_frame->settings() && m_frame->settings()->touchDragDropEnabled()) {
-        IntPoint adjustedPoint = gestureEvent.position();
-#if ENABLE(TOUCH_ADJUSTMENT)
-        adjustGesturePosition(gestureEvent, adjustedPoint);
-#endif
-        PlatformMouseEvent mouseDownEvent(adjustedPoint, gestureEvent.globalPosition(), LeftButton, PlatformEvent::MousePressed, 0, false, false, false, false, WTF::currentTime());
-        handleMousePressEvent(mouseDownEvent);
-        PlatformMouseEvent mouseDragEvent(adjustedPoint, gestureEvent.globalPosition(), LeftButton, PlatformEvent::MouseMoved, 0, false, false, false, false, WTF::currentTime());
-        HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::DisallowShadowContent);
-        MouseEventWithHitTestResults mev = prepareMouseEvent(request, mouseDragEvent);
-        m_didStartDrag = false;
-        RefPtr<Frame> subframe = subframeForHitTestResult(mev);
-        if (subframe && !m_mouseDownMayStartDrag) {
-            if (subframe->eventHandler()->handleGestureLongPress(gestureEvent))
-                return true;
-        }
-        handleDrag(mev, DontCheckDragHysteresis);
-        if (m_didStartDrag)
-            return true;
-    }
-#endif
-    return handleGestureForTextSelectionOrContextMenu(gestureEvent);
+    return true;
 }
 
-bool EventHandler::handleGestureLongTap(const PlatformGestureEvent& gestureEvent)
+void EventHandler::platformNotifyIfEndGesture(const PlatformWheelEvent&, ScrollableArea*)
 {
-#if ENABLE(CONTEXT_MENUS)
-    if (!m_didLongPressInvokeContextMenu)
-        return sendContextMenuEventForGesture(gestureEvent);
-#endif // ENABLE(CONTEXT_MENUS)
-    return false;
 }
 
-bool EventHandler::handleGestureForTextSelectionOrContextMenu(const PlatformGestureEvent& gestureEvent)
-{
-#if ENABLE(CONTEXT_MENUS)
-    m_didLongPressInvokeContextMenu = (gestureEvent.type() == PlatformEvent::GestureLongPress);
-    return sendContextMenuEventForGesture(gestureEvent);
-#else
-    return false;
 #endif
-}
 
-bool EventHandler::handleGestureTwoFingerTap(const PlatformGestureEvent& gestureEvent)
+bool EventHandler::handleWheelEvent(const PlatformWheelEvent& event)
 {
-    return handleGestureForTextSelectionOrContextMenu(gestureEvent);
-}
-
-bool EventHandler::passGestureEventToWidget(const PlatformGestureEvent& gestureEvent, Widget* widget)
-{
-    if (!widget)
-        return false;
-
-    if (!widget->isFrameView())
+    RenderView* renderView = m_frame.contentRenderer();
+    if (!renderView)
         return false;
 
-    return toFrameView(widget)->frame()->eventHandler()->handleGestureEvent(gestureEvent);
-}
+    RefPtr<FrameView> protector(m_frame.view());
 
-bool EventHandler::passGestureEventToWidgetIfPossible(const PlatformGestureEvent& gestureEvent, RenderObject* renderer)
-{
-    if (m_lastHitTestResultOverWidget && renderer && renderer->isWidget()) {
-        Widget* widget = toRenderWidget(renderer)->widget();
-        return widget && passGestureEventToWidget(gestureEvent, widget);
-    }
-    return false;
-}
-
-bool EventHandler::handleGestureScrollBegin(const PlatformGestureEvent& gestureEvent)
-{
-    Document* document = m_frame->document();
-    RenderObject* documentRenderer = document->renderer();
-    if (!documentRenderer)
-        return false;
-
-    FrameView* view = m_frame->view();
+    FrameView* view = m_frame.view();
     if (!view)
         return false;
 
-    LayoutPoint viewPoint = view->windowToContents(gestureEvent.position());
-    HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::DisallowShadowContent);
-    HitTestResult result(viewPoint);
-    document->renderView()->hitTest(request, result);
-
-    m_lastHitTestResultOverWidget = result.isOverWidget(); 
-    m_scrollGestureHandlingNode = result.innerNode();
-    m_previousGestureScrolledNode = 0;
-
-    Node* node = m_scrollGestureHandlingNode.get();
-    if (node)
-        passGestureEventToWidgetIfPossible(gestureEvent, node->renderer());
-    
-    return node && node->renderer();
-}
-
-bool EventHandler::handleGestureScrollUpdate(const PlatformGestureEvent& gestureEvent)
-{
-    FloatSize delta(gestureEvent.deltaX(), gestureEvent.deltaY());
-    if (delta.isZero())
-        return false;
-
-    const float scaleFactor = m_frame->pageZoomFactor() * m_frame->frameScaleFactor();
-    delta.scale(1 / scaleFactor, 1 / scaleFactor);
-
-    Node* node = m_scrollGestureHandlingNode.get();
-    if (!node)
-        return sendScrollEventToView(gestureEvent, delta);
-
-    // Ignore this event if the targeted node does not have a valid renderer.
-    RenderObject* renderer = node->renderer();
-    if (!renderer)
-        return false;
-
-    RefPtr<FrameView> protector(m_frame->view());
-
-    // Try to send the event to the correct view.
-    if (passGestureEventToWidgetIfPossible(gestureEvent, renderer))
-        return true;
-
-    Node* stopNode = 0;
-    bool scrollShouldNotPropagate = gestureEvent.type() == PlatformEvent::GestureScrollUpdateWithoutPropagation;
-    if (scrollShouldNotPropagate)
-        stopNode = m_previousGestureScrolledNode.get();
-
-    // First try to scroll the closest scrollable RenderBox ancestor of |node|.
-    ScrollGranularity granularity = ScrollByPixel; 
-    bool horizontalScroll = scrollNode(delta.width(), granularity, ScrollLeft, ScrollRight, node, &stopNode);
-    bool verticalScroll = scrollNode(delta.height(), granularity, ScrollUp, ScrollDown, node, &stopNode);
-
-    if (scrollShouldNotPropagate)
-        m_previousGestureScrolledNode = stopNode;
-
-    if (horizontalScroll || verticalScroll) {
-        setFrameWasScrolledByUser();
-        return true;
-    }
+    m_isHandlingWheelEvent = true;
+    setFrameWasScrolledByUser();
 
-    // Otherwise try to scroll the view.
-    return sendScrollEventToView(gestureEvent, delta);
-}
+    HitTestRequest request;
+    HitTestResult result(view->windowToContents(event.position()));
+    renderView->hitTest(request, result);
 
-bool EventHandler::sendScrollEventToView(const PlatformGestureEvent& gestureEvent, const FloatSize& scaledDelta)
-{
-    FrameView* view = m_frame->view();
-    if (!view)
-        return false;
+    RefPtr<Element> element = result.innerElement();
+    RefPtr<ContainerNode> scrollableContainer;
+    ScrollableArea* scrollableArea = nullptr;
+    bool isOverWidget = result.isOverWidget();
+    platformPrepareForWheelEvents(event, result, element, scrollableContainer, scrollableArea, isOverWidget);
 
-    const float tickDivisor = static_cast<float>(WheelEvent::TickMultiplier);
-    IntPoint point(gestureEvent.position().x(), gestureEvent.position().y());
-    IntPoint globalPoint(gestureEvent.globalPosition().x(), gestureEvent.globalPosition().y());
-    PlatformWheelEvent syntheticWheelEvent(point, globalPoint,
-        scaledDelta.width(), scaledDelta.height(), 
-        scaledDelta.width() / tickDivisor, scaledDelta.height() / tickDivisor,
-        ScrollByPixelWheelEvent,
-        gestureEvent.shiftKey(), gestureEvent.ctrlKey(), gestureEvent.altKey(), gestureEvent.metaKey());
 #if PLATFORM(MAC)
-    syntheticWheelEvent.setHasPreciseScrollingDeltas(true);
+    if (event.phase() == PlatformWheelEventPhaseNone && event.momentumPhase() == PlatformWheelEventPhaseNone)
+        m_frame.mainFrame().resetLatchingState();
 #endif
 
-    bool scrolledFrame = view->wheelEvent(syntheticWheelEvent);
-    if (scrolledFrame)
-        setFrameWasScrolledByUser();
-
-    return scrolledFrame;
-}
-
-void EventHandler::clearGestureScrollNodes()
-{
-    m_scrollGestureHandlingNode = 0;
-    m_previousGestureScrolledNode = 0;
-}
-
-bool EventHandler::isScrollbarHandlingGestures() const
-{
-    return m_scrollbarHandlingScrollGesture.get();
-}
-#endif // ENABLE(GESTURE_EVENTS)
-
-#if ENABLE(TOUCH_ADJUSTMENT)
-bool EventHandler::shouldApplyTouchAdjustment(const PlatformGestureEvent& event) const
-{
-    if (m_frame->settings() && !m_frame->settings()->touchAdjustmentEnabled())
-        return false;
-    return !event.area().isEmpty();
-}
-
-
-bool EventHandler::bestClickableNodeForTouchPoint(const IntPoint& touchCenter, const IntSize& touchRadius, IntPoint& targetPoint, Node*& targetNode)
-{
-    IntPoint hitTestPoint = m_frame->view()->windowToContents(touchCenter);
-    HitTestResult result = hitTestResultAtPoint(hitTestPoint, HitTestRequest::ReadOnly | HitTestRequest::Active, touchRadius);
+    // FIXME: It should not be necessary to do this mutation here.
+    // Instead, the handlers should know convert vertical scrolls appropriately.
+    PlatformWheelEvent adjustedEvent = event;
+    if (m_baseEventType == PlatformEvent::NoType && shouldTurnVerticalTicksIntoHorizontal(result, event))
+        adjustedEvent = event.copyTurningVerticalTicksIntoHorizontalTicks();
+
+    platformRecordWheelEvent(adjustedEvent);
+
+    if (element) {
+        if (isOverWidget) {
+            RenderElement* target = element->renderer();
+            if (is<RenderWidget>(target)) {
+                Widget* widget = downcast<RenderWidget>(*target).widget();
+                if (widget && passWheelEventToWidget(event, *widget)) {
+                    m_isHandlingWheelEvent = false;
+                    if (scrollableArea)
+                        scrollableArea->setScrolledProgrammatically(false);
+                    platformNotifyIfEndGesture(adjustedEvent, scrollableArea);
+                    if (!widget->platformWidget())
+                        return true;
+                    return platformCompletePlatformWidgetWheelEvent(event, *widget, scrollableContainer.get());
+                }
+            }
+        }
 
-    IntRect touchRect(touchCenter - touchRadius, touchRadius + touchRadius);
+        if (!element->dispatchWheelEvent(adjustedEvent)) {
+            m_isHandlingWheelEvent = false;
+            if (scrollableArea && scrollableArea->isScrolledProgrammatically()) {
+                // Web developer is controlling scrolling, so don't attempt to latch.
+                clearLatchedState();
+                scrollableArea->setScrolledProgrammatically(false);
+            }
 
-    // FIXME: Should be able to handle targetNode being a shadow DOM node to avoid performing uncessary hit tests
-    // in the case where further processing on the node is required. Returning the shadow ancestor prevents a
-    // regression in touchadjustment/html-label.html. Some refinement is required to testing/internals to
-    // handle targetNode being a shadow DOM node. 
-    bool success = findBestClickableCandidate(targetNode, targetPoint, touchCenter, touchRect, result.rectBasedTestResult());
-    if (success && targetNode)
-        targetNode = targetNode->deprecatedShadowAncestorNode();
-    return success;
-}
+            platformNotifyIfEndGesture(adjustedEvent, scrollableArea);
+            return true;
+        }
+    }
 
-bool EventHandler::bestContextMenuNodeForTouchPoint(const IntPoint& touchCenter, const IntSize& touchRadius, IntPoint& targetPoint, Node*& targetNode)
-{
-    IntPoint hitTestPoint = m_frame->view()->windowToContents(touchCenter);
-    HitTestResult result = hitTestResultAtPoint(hitTestPoint, HitTestRequest::ReadOnly | HitTestRequest::Active, touchRadius);
+    if (scrollableArea)
+        scrollableArea->setScrolledProgrammatically(false);
 
-    IntRect touchRect(touchCenter - touchRadius, touchRadius + touchRadius);
-    return findBestContextMenuCandidate(targetNode, targetPoint, touchCenter, touchRect, result.rectBasedTestResult());
+    bool handledEvent = platformCompleteWheelEvent(adjustedEvent, scrollableContainer.get(), scrollableArea);
+    platformNotifyIfEndGesture(adjustedEvent, scrollableArea);
+    return handledEvent;
 }
 
-bool EventHandler::bestZoomableAreaForTouchPoint(const IntPoint& touchCenter, const IntSize& touchRadius, IntRect& targetArea, Node*& targetNode)
+void EventHandler::clearLatchedState()
 {
-    IntPoint hitTestPoint = m_frame->view()->windowToContents(touchCenter);
-    HitTestResult result = hitTestResultAtPoint(hitTestPoint, HitTestRequest::ReadOnly | HitTestRequest::Active | HitTestRequest::DisallowShadowContent, touchRadius);
-
-    IntRect touchRect(touchCenter - touchRadius, touchRadius + touchRadius);
-    return findBestZoomableArea(targetNode, targetArea, touchCenter, touchRect, result.rectBasedTestResult());
+#if PLATFORM(MAC)
+    m_frame.mainFrame().resetLatchingState();
+#endif
+    if (auto filter = m_frame.mainFrame().wheelEventDeltaFilter())
+        filter->endFilteringDeltas();
 }
 
-bool EventHandler::adjustGesturePosition(const PlatformGestureEvent& gestureEvent, IntPoint& adjustedPoint)
+void EventHandler::defaultWheelEventHandler(Node* startNode, WheelEvent* wheelEvent)
 {
-    if (!shouldApplyTouchAdjustment(gestureEvent))
-        return false;
-
-    Node* targetNode = 0;
-    switch (gestureEvent.type()) {
-    case PlatformEvent::GestureTap:
-    case PlatformEvent::GestureTapDown:
-        bestClickableNodeForTouchPoint(gestureEvent.position(), IntSize(gestureEvent.area().width() / 2, gestureEvent.area().height() / 2), adjustedPoint, targetNode);
-        break;
-    case PlatformEvent::GestureLongPress:
-    case PlatformEvent::GestureLongTap:
-    case PlatformEvent::GestureTwoFingerTap:
-        bestContextMenuNodeForTouchPoint(gestureEvent.position(), IntSize(gestureEvent.area().width() / 2, gestureEvent.area().height() / 2), adjustedPoint, targetNode);
-        break;
-    default:
-        // FIXME: Implement handling for other types as needed.
-        ASSERT_NOT_REACHED();
+    if (!startNode || !wheelEvent)
+        return;
+    
+    FloatSize filteredPlatformDelta(wheelEvent->deltaX(), wheelEvent->deltaY());
+    if (const PlatformWheelEvent* platformWheelEvent = wheelEvent->wheelEvent()) {
+        filteredPlatformDelta.setWidth(platformWheelEvent->deltaX());
+        filteredPlatformDelta.setHeight(platformWheelEvent->deltaY());
     }
-    return targetNode;
-}
+    
+#if PLATFORM(MAC)
+    ScrollLatchingState* latchedState = m_frame.mainFrame().latchingState();
+    Element* stopElement = latchedState ? latchedState->previousWheelScrolledElement() : nullptr;
+
+    if (m_frame.mainFrame().wheelEventDeltaFilter()->isFilteringDeltas())
+        filteredPlatformDelta = m_frame.mainFrame().wheelEventDeltaFilter()->filteredDelta();
+#else
+    Element* stopElement = nullptr;
 #endif
+    
+    
+    if (handleWheelEventInAppropriateEnclosingBox(startNode, wheelEvent, &stopElement, filteredPlatformDelta))
+        wheelEvent->setDefaultHandled();
+    
+#if PLATFORM(MAC)
+    if (latchedState && !latchedState->wheelEventElement())
+        latchedState->setPreviousWheelScrolledElement(stopElement);
+#endif
+}
 
 #if ENABLE(CONTEXT_MENUS)
 bool EventHandler::sendContextMenuEvent(const PlatformMouseEvent& event)
 {
-    Document* doc = m_frame->document();
-    FrameView* v = m_frame->view();
-    if (!v)
+    Document* doc = m_frame.document();
+    FrameView* view = m_frame.view();
+    if (!view)
         return false;
-    
+
     // Clear mouse press state to avoid initiating a drag while context menu is up.
     m_mousePressed = false;
     bool swallowEvent;
-    LayoutPoint viewportPos = v->windowToContents(event.position());
+    LayoutPoint viewportPos = view->windowToContents(event.position());
     HitTestRequest request(HitTestRequest::Active | HitTestRequest::DisallowShadowContent);
-    MouseEventWithHitTestResults mev = doc->prepareMouseEvent(request, viewportPos, event);
+    MouseEventWithHitTestResults mouseEvent = doc->prepareMouseEvent(request, viewportPos, event);
 
-    if (m_frame->editor().behavior().shouldSelectOnContextualMenuClick()
-        && !m_frame->selection()->contains(viewportPos)
-        && !mev.scrollbar()
+    // Do not show context menus when clicking on scrollbars.
+    if (mouseEvent.scrollbar() || view->scrollbarAtPoint(event.position()))
+        return false;
+
+    if (m_frame.editor().behavior().shouldSelectOnContextualMenuClick()
+        && !m_frame.selection().contains(viewportPos)
         // FIXME: In the editable case, word selection sometimes selects content that isn't underneath the mouse.
         // If the selection is non-editable, we do word selection to make it easier to use the contextual menu items
         // available for text selections.  But only if we're above text.
-        && (m_frame->selection()->isContentEditable() || (mev.targetNode() && mev.targetNode()->isTextNode()))) {
+        && (m_frame.selection().selection().isContentEditable() || (mouseEvent.targetNode() && mouseEvent.targetNode()->isTextNode()))) {
         m_mouseDownMayStartSelect = true; // context menu events are always allowed to perform a selection
-        selectClosestWordOrLinkFromMouseEvent(mev);
+        selectClosestContextualWordOrLinkFromMouseEvent(mouseEvent);
     }
 
-    swallowEvent = !dispatchMouseEvent(eventNames().contextmenuEvent, mev.targetNode(), true, 0, event, false);
+    swallowEvent = !dispatchMouseEvent(eventNames().contextmenuEvent, mouseEvent.targetNode(), true, 0, event, false);
     
     return swallowEvent;
 }
 
 bool EventHandler::sendContextMenuEventForKey()
 {
-    FrameView* view = m_frame->view();
+    FrameView* view = m_frame.view();
     if (!view)
         return false;
 
-    Document* doc = m_frame->document();
+    Document* doc = m_frame.document();
     if (!doc)
         return false;
 
@@ -2926,7 +2736,7 @@ bool EventHandler::sendContextMenuEventForKey()
 
     static const int kContextMenuMargin = 1;
 
-#if OS(WINDOWS) && !OS(WINCE)
+#if OS(WINDOWS)
     int rightAligned = ::GetSystemMetrics(SM_MENUDROPALIGNMENT);
 #else
     int rightAligned = 0;
@@ -2934,12 +2744,12 @@ bool EventHandler::sendContextMenuEventForKey()
     IntPoint location;
 
     Element* focusedElement = doc->focusedElement();
-    FrameSelection* selection = m_frame->selection();
-    Position start = selection->selection().start();
+    const VisibleSelection& selection = m_frame.selection().selection();
+    Position start = selection.start();
 
-    if (start.deprecatedNode() && (selection->rootEditableElement() || selection->isRange())) {
-        RefPtr<Range> selectionRange = selection->toNormalizedRange();
-        IntRect firstRect = m_frame->editor().firstRectForRange(selectionRange.get());
+    if (start.deprecatedNode() && (selection.rootEditableElement() || selection.isRange())) {
+        RefPtr<Range> selectionRange = selection.toNormalizedRange();
+        IntRect firstRect = m_frame.editor().firstRectForRange(selectionRange.get());
 
         int x = rightAligned ? firstRect.maxX() : firstRect.x();
         // In a multiline edit, firstRect.maxY() would endup on the next line, so -1.
@@ -2957,7 +2767,7 @@ bool EventHandler::sendContextMenuEventForKey()
             kContextMenuMargin);
     }
 
-    m_frame->view()->setCursor(pointerCursor());
+    m_frame.view()->setCursor(pointerCursor());
 
     IntPoint position = view->contentsToRootView(location);
     IntPoint globalPosition = view->hostWindow()->rootViewToScreen(IntRect(position, IntSize())).location();
@@ -2980,33 +2790,10 @@ bool EventHandler::sendContextMenuEventForKey()
     PlatformEvent::Type eventType = PlatformEvent::MousePressed;
 #endif
 
-    PlatformMouseEvent mouseEvent(position, globalPosition, RightButton, eventType, 1, false, false, false, false, WTF::currentTime());
-
-    return !dispatchMouseEvent(eventNames().contextmenuEvent, targetNode, true, 0, mouseEvent, false);
-}
-
-#if ENABLE(GESTURE_EVENTS)
-bool EventHandler::sendContextMenuEventForGesture(const PlatformGestureEvent& event)
-{
-#if OS(WINDOWS)
-    PlatformEvent::Type eventType = PlatformEvent::MouseReleased;
-#else
-    PlatformEvent::Type eventType = PlatformEvent::MousePressed;
-#endif
+    PlatformMouseEvent platformMouseEvent(position, globalPosition, RightButton, eventType, 1, false, false, false, false, WTF::currentTime(), ForceAtClick);
 
-    IntPoint adjustedPoint = event.position();
-#if ENABLE(TOUCH_ADJUSTMENT)
-    adjustGesturePosition(event, adjustedPoint);
-#endif
-    PlatformMouseEvent mouseEvent(adjustedPoint, event.globalPosition(), RightButton, eventType, 1, false, false, false, false, WTF::currentTime());
-    // To simulate right-click behavior, we send a right mouse down and then
-    // context menu event.
-    handleMousePressEvent(mouseEvent);
-    return sendContextMenuEvent(mouseEvent);
-    // We do not need to send a corresponding mouse release because in case of
-    // right-click, the context menu takes capture and consumes all events.
+    return !dispatchMouseEvent(eventNames().contextmenuEvent, targetNode, true, 0, platformMouseEvent, false);
 }
-#endif // ENABLE(GESTURE_EVENTS)
 #endif // ENABLE(CONTEXT_MENUS)
 
 void EventHandler::scheduleHoverStateUpdate()
@@ -3015,41 +2802,44 @@ void EventHandler::scheduleHoverStateUpdate()
         m_hoverTimer.startOneShot(0);
 }
 
+#if ENABLE(CURSOR_SUPPORT)
 void EventHandler::scheduleCursorUpdate()
 {
     if (!m_cursorUpdateTimer.isActive())
         m_cursorUpdateTimer.startOneShot(cursorUpdateInterval);
 }
+#endif
 
 void EventHandler::dispatchFakeMouseMoveEventSoon()
 {
+#if !ENABLE(IOS_TOUCH_EVENTS)
     if (m_mousePressed)
         return;
 
     if (m_mousePositionIsUnknown)
         return;
 
-    Settings* settings = m_frame->settings();
-    if (settings && !settings->deviceSupportsMouse())
-        return;
+    if (Page* page = m_frame.page()) {
+        if (!page->chrome().client().shouldDispatchFakeMouseMoveEvents())
+            return;
+    }
 
     // If the content has ever taken longer than fakeMouseMoveShortInterval we
     // reschedule the timer and use a longer time. This will cause the content
     // to receive these moves only after the user is done scrolling, reducing
     // pauses during the scroll.
-    if (m_maxMouseMovedDuration > fakeMouseMoveShortInterval) {
-        if (m_fakeMouseMoveEventTimer.isActive())
-            m_fakeMouseMoveEventTimer.stop();
-        m_fakeMouseMoveEventTimer.startOneShot(fakeMouseMoveLongInterval);
-    } else {
-        if (!m_fakeMouseMoveEventTimer.isActive())
-            m_fakeMouseMoveEventTimer.startOneShot(fakeMouseMoveShortInterval);
-    }
+    if (m_fakeMouseMoveEventTimer.isActive())
+        m_fakeMouseMoveEventTimer.stop();
+    m_fakeMouseMoveEventTimer.startOneShot(m_maxMouseMovedDuration > fakeMouseMoveDurationThreshold ? fakeMouseMoveLongInterval : fakeMouseMoveShortInterval);
+#endif
 }
 
 void EventHandler::dispatchFakeMouseMoveEventSoonInQuad(const FloatQuad& quad)
 {
-    FrameView* view = m_frame->view();
+#if ENABLE(IOS_TOUCH_EVENTS)
+    UNUSED_PARAM(quad);
+#else
+    FrameView* view = m_frame.view();
     if (!view)
         return;
 
@@ -3057,27 +2847,24 @@ void EventHandler::dispatchFakeMouseMoveEventSoonInQuad(const FloatQuad& quad)
         return;
 
     dispatchFakeMouseMoveEventSoon();
+#endif
 }
 
+#if !ENABLE(IOS_TOUCH_EVENTS)
 void EventHandler::cancelFakeMouseMoveEvent()
 {
     m_fakeMouseMoveEventTimer.stop();
 }
 
-void EventHandler::fakeMouseMoveEventTimerFired(Timer<EventHandler>* timer)
+void EventHandler::fakeMouseMoveEventTimerFired()
 {
-    ASSERT_UNUSED(timer, timer == &m_fakeMouseMoveEventTimer);
     ASSERT(!m_mousePressed);
 
-    Settings* settings = m_frame->settings();
-    if (settings && !settings->deviceSupportsMouse())
-        return;
-
-    FrameView* view = m_frame->view();
+    FrameView* view = m_frame.view();
     if (!view)
         return;
 
-    if (!m_frame->page() || !m_frame->page()->isOnscreen() || !m_frame->page()->focusController()->isActive())
+    if (!m_frame.page() || !m_frame.page()->isVisible() || !m_frame.page()->focusController().isActive())
         return;
 
     bool shiftKey;
@@ -3085,9 +2872,10 @@ void EventHandler::fakeMouseMoveEventTimerFired(Timer<EventHandler>* timer)
     bool altKey;
     bool metaKey;
     PlatformKeyboardEvent::getCurrentModifierState(shiftKey, ctrlKey, altKey, metaKey);
-    PlatformMouseEvent fakeMouseMoveEvent(m_lastKnownMousePosition, m_lastKnownMouseGlobalPosition, NoButton, PlatformEvent::MouseMoved, 0, shiftKey, ctrlKey, altKey, metaKey, currentTime());
+    PlatformMouseEvent fakeMouseMoveEvent(m_lastKnownMousePosition, m_lastKnownMouseGlobalPosition, NoButton, PlatformEvent::MouseMoved, 0, shiftKey, ctrlKey, altKey, metaKey, currentTime(), 0);
     mouseMoved(fakeMouseMoveEvent);
 }
+#endif // !ENABLE(IOS_TOUCH_EVENTS)
 
 void EventHandler::setResizingFrameSet(HTMLFrameSetElement* frameSet)
 {
@@ -3097,40 +2885,38 @@ void EventHandler::setResizingFrameSet(HTMLFrameSetElement* frameSet)
 void EventHandler::resizeLayerDestroyed()
 {
     ASSERT(m_resizeLayer);
-    m_resizeLayer = 0;
+    m_resizeLayer = nullptr;
 }
 
-void EventHandler::hoverTimerFired(Timer<EventHandler>*)
+void EventHandler::hoverTimerFired()
 {
     m_hoverTimer.stop();
 
-    ASSERT(m_frame);
-    ASSERT(m_frame->document());
+    ASSERT(m_frame.document());
 
-    if (RenderView* renderer = m_frame->contentRenderer()) {
-        if (FrameView* view = m_frame->view()) {
+    if (RenderView* renderView = m_frame.contentRenderer()) {
+        if (FrameView* view = m_frame.view()) {
             HitTestRequest request(HitTestRequest::Move | HitTestRequest::DisallowShadowContent);
             HitTestResult result(view->windowToContents(m_lastKnownMousePosition));
-            renderer->hitTest(request, result);
-            m_frame->document()->updateHoverActiveState(request, result.innerElement());
+            renderView->hitTest(request, result);
+            m_frame.document()->updateHoverActiveState(request, result.innerElement());
         }
     }
 }
 
-bool EventHandler::handleAccessKey(const PlatformKeyboardEvent& evt)
+bool EventHandler::handleAccessKey(const PlatformKeyboardEvent& event)
 {
     // FIXME: Ignoring the state of Shift key is what neither IE nor Firefox do.
     // IE matches lower and upper case access keys regardless of Shift key state - but if both upper and
     // lower case variants are present in a document, the correct element is matched based on Shift key state.
     // Firefox only matches an access key if Shift is not pressed, and does that case-insensitively.
     ASSERT(!(accessKeyModifiers() & PlatformEvent::ShiftKey));
-    if ((evt.modifiers() & ~PlatformEvent::ShiftKey) != accessKeyModifiers())
+    if ((event.modifiers() & ~PlatformEvent::ShiftKey) != accessKeyModifiers())
         return false;
-    String key = evt.unmodifiedText();
-    Element* elem = m_frame->document()->getElementByAccessKey(key.lower());
-    if (!elem)
+    Element* element = m_frame.document()->getElementByAccessKey(event.unmodifiedText());
+    if (!element)
         return false;
-    elem->accessKeyAction(false);
+    element->accessKeyAction(false);
     return true;
 }
 
@@ -3144,7 +2930,7 @@ bool EventHandler::needsKeyboardEventDisambiguationQuirks() const
 #if ENABLE(FULLSCREEN_API)
 bool EventHandler::isKeyEventAllowedInFullScreen(const PlatformKeyboardEvent& keyEvent) const
 {
-    Document* document = m_frame->document();
+    Document* document = m_frame.document();
     if (document->webkitFullScreenKeyboardInputAllowed())
         return true;
 
@@ -3165,43 +2951,45 @@ bool EventHandler::isKeyEventAllowedInFullScreen(const PlatformKeyboardEvent& ke
 
 bool EventHandler::keyEvent(const PlatformKeyboardEvent& initialKeyEvent)
 {
-    RefPtr<FrameView> protector(m_frame->view()); 
+    RefPtr<FrameView> protector(m_frame.view());
 
 #if ENABLE(FULLSCREEN_API)
-    if (m_frame->document()->webkitIsFullScreen() && !isKeyEventAllowedInFullScreen(initialKeyEvent))
+    if (m_frame.document()->webkitIsFullScreen() && !isKeyEventAllowedInFullScreen(initialKeyEvent))
         return false;
 #endif
 
-    if (initialKeyEvent.windowsVirtualKeyCode() == VK_CAPITAL)
-        capsLockStateMayHaveChanged();
+    if (initialKeyEvent.windowsVirtualKeyCode() == VK_CAPITAL) {
+        if (auto* element = m_frame.document()->focusedElement()) {
+            if (is<HTMLInputElement>(*element))
+                downcast<HTMLInputElement>(*element).capsLockStateMayHaveChanged();
+        }
+    }
 
 #if ENABLE(PAN_SCROLLING)
-    if (Page* page = m_frame->page()) {
-        if (page->mainFrame()->eventHandler()->panScrollInProgress()) {
-            // If a key is pressed while the panScroll is in progress then we want to stop
-            if (initialKeyEvent.type() == PlatformEvent::KeyDown || initialKeyEvent.type() == PlatformEvent::RawKeyDown) 
-                stopAutoscrollTimer();
+    if (m_frame.mainFrame().eventHandler().panScrollInProgress()) {
+        // If a key is pressed while the panScroll is in progress then we want to stop
+        if (initialKeyEvent.type() == PlatformEvent::KeyDown || initialKeyEvent.type() == PlatformEvent::RawKeyDown)
+            stopAutoscrollTimer();
 
-            // If we were in panscroll mode, we swallow the key event
-            return true;
-        }
+        // If we were in panscroll mode, we swallow the key event
+        return true;
     }
 #endif
 
     // Check for cases where we are too early for events -- possible unmatched key up
     // from pressing return in the location bar.
-    RefPtr<Node> node = eventTargetNodeForDocument(m_frame->document());
-    if (!node)
+    RefPtr<Element> element = eventTargetElementForDocument(m_frame.document());
+    if (!element)
         return false;
 
-    UserGestureIndicator gestureIndicator(DefinitelyProcessingUserGesture);
+    UserGestureIndicator gestureIndicator(DefinitelyProcessingUserGesture, m_frame.document());
     UserTypingGestureIndicator typingGestureIndicator(m_frame);
 
-    if (FrameView* view = m_frame->view())
-        view->resetDeferredRepaintDelay();
+    if (FrameView* view = m_frame.view())
+        view->disableLayerFlushThrottlingTemporarilyForInteraction();
 
     // FIXME (bug 68185): this call should be made at another abstraction layer
-    m_frame->loader()->resetMultipleFormSubmissionProtection();
+    m_frame.loader().resetMultipleFormSubmissionProtection();
 
     // In IE, access keys are special, they are handled after default keydown processing, but cannot be canceled - this is hard to match.
     // On Mac OS X, we process them before dispatching keydown, as the default keydown handler implements Emacs key bindings, which may conflict
@@ -3214,22 +3002,22 @@ bool EventHandler::keyEvent(const PlatformKeyboardEvent& initialKeyEvent)
 
     // FIXME: it would be fair to let an input method handle KeyUp events before DOM dispatch.
     if (initialKeyEvent.type() == PlatformEvent::KeyUp || initialKeyEvent.type() == PlatformEvent::Char)
-        return !node->dispatchKeyEvent(initialKeyEvent);
+        return !element->dispatchKeyEvent(initialKeyEvent);
 
     bool backwardCompatibilityMode = needsKeyboardEventDisambiguationQuirks();
 
     PlatformKeyboardEvent keyDownEvent = initialKeyEvent;    
     if (keyDownEvent.type() != PlatformEvent::RawKeyDown)
         keyDownEvent.disambiguateKeyDownEvent(PlatformEvent::RawKeyDown, backwardCompatibilityMode);
-    RefPtr<KeyboardEvent> keydown = KeyboardEvent::create(keyDownEvent, m_frame->document()->defaultView());
+    Ref<KeyboardEvent> keydown = KeyboardEvent::create(keyDownEvent, m_frame.document()->defaultView());
     if (matchedAnAccessKey)
         keydown->setDefaultPrevented(true);
-    keydown->setTarget(node);
+    keydown->setTarget(element);
 
     if (initialKeyEvent.type() == PlatformEvent::RawKeyDown) {
-        node->dispatchEvent(keydown, IGNORE_EXCEPTION);
+        element->dispatchEvent(keydown);
         // If frame changed as a result of keydown dispatch, then return true to avoid sending a subsequent keypress message to the new frame.
-        bool changedFocusedFrame = m_frame->page() && m_frame != m_frame->page()->focusController()->focusedOrMainFrame();
+        bool changedFocusedFrame = m_frame.page() && &m_frame != &m_frame.page()->focusController().focusedOrMainFrame();
         return keydown->defaultHandled() || keydown->defaultPrevented() || changedFocusedFrame;
     }
 
@@ -3238,29 +3026,32 @@ bool EventHandler::keyEvent(const PlatformKeyboardEvent& initialKeyEvent)
     // in order to match IE:
     // 1. preventing default handling of keydown and keypress events has no effect on IM input;
     // 2. if an input method handles the event, its keyCode is set to 229 in keydown event.
-    m_frame->editor().handleInputMethodKeydown(keydown.get());
+    m_frame.editor().handleInputMethodKeydown(keydown.ptr());
     
     bool handledByInputMethod = keydown->defaultHandled();
     
     if (handledByInputMethod) {
         keyDownEvent.setWindowsVirtualKeyCode(CompositionEventKeyCode);
-        keydown = KeyboardEvent::create(keyDownEvent, m_frame->document()->defaultView());
-        keydown->setTarget(node);
+        keydown = KeyboardEvent::create(keyDownEvent, m_frame.document()->defaultView());
+        keydown->setTarget(element);
         keydown->setDefaultHandled();
     }
+    
+    if (accessibilityPreventsEventPropogation(keydown))
+        keydown->stopPropagation();
 
-    node->dispatchEvent(keydown, IGNORE_EXCEPTION);
+    element->dispatchEvent(keydown);
     // If frame changed as a result of keydown dispatch, then return early to avoid sending a subsequent keypress message to the new frame.
-    bool changedFocusedFrame = m_frame->page() && m_frame != m_frame->page()->focusController()->focusedOrMainFrame();
+    bool changedFocusedFrame = m_frame.page() && &m_frame != &m_frame.page()->focusController().focusedOrMainFrame();
     bool keydownResult = keydown->defaultHandled() || keydown->defaultPrevented() || changedFocusedFrame;
     if (handledByInputMethod || (keydownResult && !backwardCompatibilityMode))
         return keydownResult;
     
-    // Focus may have changed during keydown handling, so refetch node.
-    // But if we are dispatching a fake backward compatibility keypress, then we pretend that the keypress happened on the original node.
+    // Focus may have changed during keydown handling, so refetch element.
+    // But if we are dispatching a fake backward compatibility keypress, then we pretend that the keypress happened on the original element.
     if (!keydownResult) {
-        node = eventTargetNodeForDocument(m_frame->document());
-        if (!node)
+        element = eventTargetElementForDocument(m_frame.document());
+        if (!element)
             return false;
     }
 
@@ -3268,24 +3059,24 @@ bool EventHandler::keyEvent(const PlatformKeyboardEvent& initialKeyEvent)
     keyPressEvent.disambiguateKeyDownEvent(PlatformEvent::Char, backwardCompatibilityMode);
     if (keyPressEvent.text().isEmpty())
         return keydownResult;
-    RefPtr<KeyboardEvent> keypress = KeyboardEvent::create(keyPressEvent, m_frame->document()->defaultView());
-    keypress->setTarget(node);
+    Ref<KeyboardEvent> keypress = KeyboardEvent::create(keyPressEvent, m_frame.document()->defaultView());
+    keypress->setTarget(element);
     if (keydownResult)
         keypress->setDefaultPrevented(true);
-#if PLATFORM(MAC)
+#if PLATFORM(COCOA)
     keypress->keypressCommands() = keydown->keypressCommands();
 #endif
-    node->dispatchEvent(keypress, IGNORE_EXCEPTION);
+    element->dispatchEvent(keypress);
 
     return keydownResult || keypress->defaultPrevented() || keypress->defaultHandled();
 }
 
 static FocusDirection focusDirectionForKey(const AtomicString& keyIdentifier)
 {
-    DEFINE_STATIC_LOCAL(AtomicString, Down, ("Down", AtomicString::ConstructFromLiteral));
-    DEFINE_STATIC_LOCAL(AtomicString, Up, ("Up", AtomicString::ConstructFromLiteral));
-    DEFINE_STATIC_LOCAL(AtomicString, Left, ("Left", AtomicString::ConstructFromLiteral));
-    DEFINE_STATIC_LOCAL(AtomicString, Right, ("Right", AtomicString::ConstructFromLiteral));
+    static NeverDestroyed<AtomicString> Down("Down", AtomicString::ConstructFromLiteral);
+    static NeverDestroyed<AtomicString> Up("Up", AtomicString::ConstructFromLiteral);
+    static NeverDestroyed<AtomicString> Left("Left", AtomicString::ConstructFromLiteral);
+    static NeverDestroyed<AtomicString> Right("Right", AtomicString::ConstructFromLiteral);
 
     FocusDirection retVal = FocusDirectionNone;
 
@@ -3301,14 +3092,53 @@ static FocusDirection focusDirectionForKey(const AtomicString& keyIdentifier)
     return retVal;
 }
 
-static void handleKeyboardSelectionMovement(FrameSelection* selection, KeyboardEvent* event)
+static void setInitialKeyboardSelection(Frame& frame, SelectionDirection direction)
+{
+    Document* document = frame.document();
+    if (!document)
+        return;
+
+    FrameSelection& selection = frame.selection();
+
+    if (!selection.isNone())
+        return;
+
+    Element* focusedElement = document->focusedElement();
+    VisiblePosition visiblePosition;
+
+    switch (direction) {
+    case DirectionBackward:
+    case DirectionLeft:
+        if (focusedElement)
+            visiblePosition = VisiblePosition(positionBeforeNode(focusedElement));
+        else
+            visiblePosition = endOfDocument(document);
+        break;
+    case DirectionForward:
+    case DirectionRight:
+        if (focusedElement)
+            visiblePosition = VisiblePosition(positionAfterNode(focusedElement));
+        else
+            visiblePosition = startOfDocument(document);
+        break;
+    }
+
+    AXTextStateChangeIntent intent(AXTextStateChangeTypeSelectionMove, AXTextSelection { AXTextSelectionDirectionDiscontiguous, AXTextSelectionGranularityUnknown, false });
+    selection.setSelection(visiblePosition, FrameSelection::defaultSetSelectionOptions(UserTriggered), intent);
+}
+
+static void handleKeyboardSelectionMovement(Frame& frame, KeyboardEvent* event)
 {
     if (!event)
         return;
 
-    bool isOptioned = event->getModifierState("Alt");
+    FrameSelection& selection = frame.selection();
+
     bool isCommanded = event->getModifierState("Meta");
+    bool isOptioned = event->getModifierState("Alt");
+    bool isSelection = !selection.isNone();
 
+    FrameSelection::EAlteration alternation = event->getModifierState("Shift") ? FrameSelection::AlterationExtend : FrameSelection::AlterationMove;
     SelectionDirection direction = DirectionForward;
     TextGranularity granularity = CharacterGranularity;
 
@@ -3337,15 +3167,47 @@ static void handleKeyboardSelectionMovement(FrameSelection* selection, KeyboardE
         break;
     }
 
-    FrameSelection::EAlteration alternation = event->getModifierState("Shift") ? FrameSelection::AlterationExtend : FrameSelection::AlterationMove;
-    selection->modify(alternation, direction, granularity, UserTriggered);
+    if (isSelection)
+        selection.modify(alternation, direction, granularity, UserTriggered);
+    else
+        setInitialKeyboardSelection(frame, direction);
+
     event->setDefaultHandled();
 }
-    
+
+void EventHandler::handleKeyboardSelectionMovementForAccessibility(KeyboardEvent* event)
+{
+    if (event->type() == eventNames().keydownEvent) {
+        if (AXObjectCache::accessibilityEnhancedUserInterfaceEnabled())
+            handleKeyboardSelectionMovement(m_frame, event);
+    }
+}
+
+bool EventHandler::accessibilityPreventsEventPropogation(KeyboardEvent& event)
+{
+#if PLATFORM(COCOA)
+    if (!AXObjectCache::accessibilityEnhancedUserInterfaceEnabled())
+        return false;
+
+    if (!m_frame.settings().preventKeyboardDOMEventDispatch())
+        return false;
+
+    // Check for key events that are relevant to accessibility: tab and arrows keys that change focus
+    if (event.keyIdentifier() == "U+0009")
+        return true;
+    FocusDirection direction = focusDirectionForKey(event.keyIdentifier());
+    if (direction != FocusDirectionNone)
+        return true;
+#else
+    UNUSED_PARAM(event);
+#endif
+    return false;
+}
+
 void EventHandler::defaultKeyboardEventHandler(KeyboardEvent* event)
 {
     if (event->type() == eventNames().keydownEvent) {
-        m_frame->editor().handleKeyboardEvent(event);
+        m_frame.editor().handleKeyboardEvent(event);
         if (event->defaultHandled())
             return;
         if (event->keyIdentifier() == "U+0009")
@@ -3358,12 +3220,10 @@ void EventHandler::defaultKeyboardEventHandler(KeyboardEvent* event)
                 defaultArrowEventHandler(direction, event);
         }
 
-        // provides KB navigation and selection for enhanced accessibility users
-        if (AXObjectCache::accessibilityEnhancedUserInterfaceEnabled())
-            handleKeyboardSelectionMovement(m_frame->selection(), event);
+        handleKeyboardSelectionMovementForAccessibility(event);
     }
     if (event->type() == eventNames().keypressEvent) {
-        m_frame->editor().handleKeyboardEvent(event);
+        m_frame.editor().handleKeyboardEvent(event);
         if (event->defaultHandled())
             return;
         if (event->charCode() == ' ')
@@ -3380,18 +3240,15 @@ bool EventHandler::dragHysteresisExceeded(const IntPoint& floatDragViewportLocat
 
 bool EventHandler::dragHysteresisExceeded(const FloatPoint& dragViewportLocation) const
 {
-    FrameView* view = m_frame->view();
-    if (!view)
-        return false;
-    IntPoint dragLocation = view->windowToContents(flooredIntPoint(dragViewportLocation));
-    IntSize delta = dragLocation - m_mouseDownPos;
-    
     int threshold = GeneralDragHysteresis;
     switch (dragState().type) {
     case DragSourceActionSelection:
         threshold = TextDragHysteresis;
         break;
     case DragSourceActionImage:
+#if ENABLE(ATTACHMENT_ELEMENT)
+    case DragSourceActionAttachment:
+#endif
         threshold = ImageDragHysteresis;
         break;
     case DragSourceActionLink:
@@ -3404,15 +3261,15 @@ bool EventHandler::dragHysteresisExceeded(const FloatPoint& dragViewportLocation
         ASSERT_NOT_REACHED();
     }
     
-    return abs(delta.width()) >= threshold || abs(delta.height()) >= threshold;
+    return mouseMovementExceedsThreshold(dragViewportLocation, threshold);
 }
     
-void EventHandler::freeClipboard()
+void EventHandler::freeDataTransfer()
 {
-    if (!dragState().clipboard)
+    if (!dragState().dataTransfer)
         return;
-    dragState().clipboard->setAccessPolicy(ClipboardNumb);
-    dragState().clipboard = 0;
+    dragState().dataTransfer->setAccessPolicy(DataTransferAccessPolicy::Numb);
+    dragState().dataTransfer = nullptr;
 }
 
 void EventHandler::dragSourceEndedAt(const PlatformMouseEvent& event, DragOperation operation)
@@ -3422,12 +3279,12 @@ void EventHandler::dragSourceEndedAt(const PlatformMouseEvent& event, DragOperat
     prepareMouseEvent(request, event);
 
     if (dragState().source && dragState().shouldDispatchEvents) {
-        dragState().clipboard->setDestinationOperation(operation);
+        dragState().dataTransfer->setDestinationOperation(operation);
         // For now we don't care if event handler cancels default behavior, since there is no default behavior.
         dispatchDragSrcEvent(eventNames().dragendEvent, event);
     }
-    freeClipboard();
-    dragState().source = 0;
+    freeDataTransfer();
+    dragState().source = nullptr;
     // In case the drag was ended due to an escape key press we need to ensure
     // that consecutive mousemove events don't reinitiate the drag and drop.
     m_mouseDownMayStartDrag = false;
@@ -3443,7 +3300,7 @@ void EventHandler::updateDragStateAfterEditDragIfNeeded(Element* rootEditableEle
 // Return value indicates if we should continue "default processing", i.e., whether event handler canceled.
 bool EventHandler::dispatchDragSrcEvent(const AtomicString& eventType, const PlatformMouseEvent& event)
 {
-    return !dispatchDragEvent(eventType, dragState().source.get(), event, dragState().clipboard.get());
+    return !dispatchDragEvent(eventType, *dragState().source, event, dragState().dataTransfer.get());
 }
     
 static bool ExactlyOneBitSet(DragSourceAction n)
@@ -3473,9 +3330,9 @@ bool EventHandler::handleDrag(const MouseEventWithHitTestResults& event, CheckDr
         // try to find an element that wants to be dragged
         HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::DisallowShadowContent);
         HitTestResult result(m_mouseDownPos);
-        m_frame->contentRenderer()->hitTest(request, result);
-        if (m_frame->page())
-            dragState().source = m_frame->page()->dragController()->draggableElement(m_frame, result.innerElement(), m_mouseDownPos, dragState());
+        m_frame.contentRenderer()->hitTest(request, result);
+        if (m_frame.page())
+            dragState().source = m_frame.page()->dragController().draggableElement(&m_frame, result.innerElement(), m_mouseDownPos, dragState());
         
         if (!dragState().source)
             m_mouseDownMayStartDrag = false; // no element is draggable
@@ -3493,7 +3350,7 @@ bool EventHandler::handleDrag(const MouseEventWithHitTestResults& event, CheckDr
         } else if (!(dragState().type & (DragSourceActionDHTML | DragSourceActionLink))) {
             // ... but only bail if we're not over an unselectable element.
             m_mouseDownMayStartDrag = false;
-            dragState().source = 0;
+            dragState().source = nullptr;
             // ... but if this was the first click in the window, we don't even want to start selection
             if (eventActivatedView(event.event()))
                 m_mouseDownMayStartSelect = false;
@@ -3512,14 +3369,21 @@ bool EventHandler::handleDrag(const MouseEventWithHitTestResults& event, CheckDr
     
     if (!ExactlyOneBitSet(dragState().type)) {
         ASSERT((dragState().type & DragSourceActionSelection));
+#if ENABLE(ATTACHMENT_ELEMENT)
+        ASSERT((dragState().type & ~DragSourceActionSelection) == DragSourceActionDHTML
+               || (dragState().type & ~DragSourceActionSelection) == DragSourceActionImage
+               || (dragState().type & ~DragSourceActionSelection) == DragSourceActionAttachment
+               || (dragState().type & ~DragSourceActionSelection) == DragSourceActionLink);
+#else
         ASSERT((dragState().type & ~DragSourceActionSelection) == DragSourceActionDHTML
             || (dragState().type & ~DragSourceActionSelection) == DragSourceActionImage
             || (dragState().type & ~DragSourceActionSelection) == DragSourceActionLink);
+#endif
         dragState().type = DragSourceActionSelection;
     }
 
     // We are starting a text/image/url drag, so the cursor should be an arrow
-    if (FrameView* view = m_frame->view()) {
+    if (FrameView* view = m_frame.view()) {
         // FIXME <rdar://7577595>: Custom cursors aren't supported during drag and drop (default to pointer).
         view->setCursor(pointerCursor());
     }
@@ -3532,10 +3396,10 @@ bool EventHandler::handleDrag(const MouseEventWithHitTestResults& event, CheckDr
     
     DragOperation srcOp = DragOperationNone;      
     
-    // This does work only if we missed a dragEnd. Do it anyway, just to make sure the old clipboard gets numbed.
-    freeClipboard();
+    // This does work only if we missed a dragEnd. Do it anyway, just to make sure the old dataTransfer gets numbed.
+    freeDataTransfer();
 
-    dragState().clipboard = createDraggingClipboard();
+    dragState().dataTransfer = createDraggingDataTransfer();
     
     if (dragState().shouldDispatchEvents) {
         // Check to see if the is a DOM based drag. If it is, get the DOM specified drag image and offset.
@@ -3544,7 +3408,7 @@ bool EventHandler::handleDrag(const MouseEventWithHitTestResults& event, CheckDr
                 // FIXME: This doesn't work correctly with transforms.
                 FloatPoint absPos = renderer->localToAbsolute();
                 IntSize delta = m_mouseDownPos - roundedIntPoint(absPos);
-                dragState().clipboard->setDragImage(dragState().source.get(), delta.width(), delta.height());
+                dragState().dataTransfer->setDragImage(dragState().source.get(), delta.width(), delta.height());
             } else {
                 // The renderer has disappeared, this can happen if the onStartDrag handler has hidden
                 // the element in some way.  In this case we just kill the drag.
@@ -3554,27 +3418,26 @@ bool EventHandler::handleDrag(const MouseEventWithHitTestResults& event, CheckDr
         } 
         
         m_mouseDownMayStartDrag = dispatchDragSrcEvent(eventNames().dragstartEvent, m_mouseDown)
-            && !m_frame->selection()->isInPasswordField();
+            && !m_frame.selection().selection().isInPasswordField();
         
-        // Invalidate clipboard here against anymore pasteboard writing for security.  The drag
+        // Invalidate dataTransfer here against anymore pasteboard writing for security. The drag
         // image can still be changed as we drag, but not the pasteboard data.
-        dragState().clipboard->setAccessPolicy(ClipboardImageWritable);
+        dragState().dataTransfer->setAccessPolicy(DataTransferAccessPolicy::ImageWritable);
         
         if (m_mouseDownMayStartDrag) {
             // Gather values from DHTML element, if it set any.
-            srcOp = dragState().clipboard->sourceOperation();
+            srcOp = dragState().dataTransfer->sourceOperation();
             
             // Yuck, a draggedImage:moveTo: message can be fired as a result of kicking off the
             // drag with dragImage! Because of that dumb reentrancy, we may think we've not
             // started the drag when that happens. So we have to assume it's started before we kick it off.
-            dragState().clipboard->setDragHasStarted();
+            dragState().dataTransfer->setDragHasStarted();
         }
     }
     
     if (m_mouseDownMayStartDrag) {
-        Page* page = m_frame->page();
-        DragController* dragController = page ? page->dragController() : 0;
-        m_didStartDrag = dragController && dragController->startDrag(m_frame, dragState(), srcOp, event.event(), m_mouseDownPos);
+        Page* page = m_frame.page();
+        m_didStartDrag = page && page->dragController().startDrag(m_frame, dragState(), srcOp, event.event(), m_mouseDownPos);
         // In WebKit2 we could re-enter this code and start another drag.
         // On OS X this causes problems with the ownership of the pasteboard and the promised types.
         if (m_didStartDrag) {
@@ -3591,39 +3454,47 @@ bool EventHandler::handleDrag(const MouseEventWithHitTestResults& event, CheckDr
 cleanupDrag:
     if (!m_mouseDownMayStartDrag) {
         // Something failed to start the drag, clean up.
-        freeClipboard();
-        dragState().source = 0;
+        freeDataTransfer();
+        dragState().source = nullptr;
     }
     
     // No more default handling (like selection), whether we're past the hysteresis bounds or not
     return true;
 }
 #endif // ENABLE(DRAG_SUPPORT)
-  
+
+bool EventHandler::mouseMovementExceedsThreshold(const FloatPoint& viewportLocation, int pointsThreshold) const
+{
+    FrameView* view = m_frame.view();
+    if (!view)
+        return false;
+    IntPoint location = view->windowToContents(flooredIntPoint(viewportLocation));
+    IntSize delta = location - m_mouseDownPos;
+    
+    return abs(delta.width()) >= pointsThreshold || abs(delta.height()) >= pointsThreshold;
+}
+
 bool EventHandler::handleTextInputEvent(const String& text, Event* underlyingEvent, TextEventInputType inputType)
 {
     // Platforms should differentiate real commands like selectAll from text input in disguise (like insertNewline),
     // and avoid dispatching text input events from keydown default handlers.
-    ASSERT(!underlyingEvent || !underlyingEvent->isKeyboardEvent() || static_cast<KeyboardEvent*>(underlyingEvent)->type() == eventNames().keypressEvent);
-
-    if (!m_frame)
-        return false;
+    ASSERT(!is<KeyboardEvent>(underlyingEvent) || downcast<KeyboardEvent>(*underlyingEvent).type() == eventNames().keypressEvent);
 
     EventTarget* target;
     if (underlyingEvent)
         target = underlyingEvent->target();
     else
-        target = eventTargetNodeForDocument(m_frame->document());
+        target = eventTargetElementForDocument(m_frame.document());
     if (!target)
         return false;
     
-    if (FrameView* view = m_frame->view())
-        view->resetDeferredRepaintDelay();
+    if (FrameView* view = m_frame.view())
+        view->disableLayerFlushThrottlingTemporarilyForInteraction();
 
-    RefPtr<TextEvent> event = TextEvent::create(m_frame->document()->domWindow(), text, inputType);
+    Ref<TextEvent> event = TextEvent::create(m_frame.document()->domWindow(), text, inputType);
     event->setUnderlyingEvent(underlyingEvent);
 
-    target->dispatchEvent(event, IGNORE_EXCEPTION);
+    target->dispatchEvent(event);
     return event->defaultHandled();
 }
     
@@ -3637,9 +3508,10 @@ bool EventHandler::isKeyboardOptionTab(KeyboardEvent* event)
 
 bool EventHandler::eventInvertsTabsToLinksClientCallResult(KeyboardEvent* event)
 {
-#if PLATFORM(MAC) || PLATFORM(QT) || PLATFORM(EFL)
+#if PLATFORM(COCOA) || PLATFORM(QT) || PLATFORM(EFL)
     return EventHandler::isKeyboardOptionTab(event);
 #else
+    UNUSED_PARAM(event);
     return false;
 #endif
 }
@@ -3648,17 +3520,17 @@ bool EventHandler::tabsToLinks(KeyboardEvent* event) const
 {
     // FIXME: This function needs a better name. It can be called for keypresses other than Tab when spatial navigation is enabled.
 
-    Page* page = m_frame->page();
+    Page* page = m_frame.page();
     if (!page)
         return false;
 
-    bool tabsToLinksClientCallResult = page->chrome().client()->keyboardUIMode() & KeyboardAccessTabsToLinks;
+    bool tabsToLinksClientCallResult = page->chrome().client().keyboardUIMode() & KeyboardAccessTabsToLinks;
     return eventInvertsTabsToLinksClientCallResult(event) ? !tabsToLinksClientCallResult : tabsToLinksClientCallResult;
 }
 
 void EventHandler::defaultTextInputEventHandler(TextEvent* event)
 {
-    if (m_frame->editor().handleTextEvent(event))
+    if (m_frame.editor().handleTextEvent(event))
         event->setDefaultHandled();
 }
 
@@ -3676,7 +3548,7 @@ void EventHandler::defaultSpaceEventHandler(KeyboardEvent* event)
         return;
     }
 
-    FrameView* view = m_frame->view();
+    FrameView* view = m_frame.view();
     if (!view)
         return;
 
@@ -3691,22 +3563,22 @@ void EventHandler::defaultBackspaceEventHandler(KeyboardEvent* event)
     if (event->ctrlKey() || event->metaKey() || event->altKey() || event->altGraphKey())
         return;
 
-    if (!m_frame->editor().behavior().shouldNavigateBackOnBackspace())
+    if (!m_frame.editor().behavior().shouldNavigateBackOnBackspace())
         return;
     
-    Page* page = m_frame->page();
+    Page* page = m_frame.page();
     if (!page)
         return;
 
-    if (!m_frame->settings()->backspaceKeyNavigationEnabled())
+    if (!m_frame.settings().backspaceKeyNavigationEnabled())
         return;
     
     bool handledEvent = false;
 
     if (event->shiftKey())
-        handledEvent = page->goForward();
+        handledEvent = page->backForward().goForward();
     else
-        handledEvent = page->goBack();
+        handledEvent = page->backForward().goBack();
 
     if (handledEvent)
         event->setDefaultHandled();
@@ -3720,19 +3592,19 @@ void EventHandler::defaultArrowEventHandler(FocusDirection focusDirection, Keybo
     if (event->ctrlKey() || event->metaKey() || event->altGraphKey() || event->shiftKey())
         return;
 
-    Page* page = m_frame->page();
+    Page* page = m_frame.page();
     if (!page)
         return;
 
-    if (!isSpatialNavigationEnabled(m_frame))
+    if (!isSpatialNavigationEnabled(&m_frame))
         return;
 
     // Arrows and other possible directional navigation keys can be used in design
     // mode editing.
-    if (m_frame->document()->inDesignMode())
+    if (m_frame.document()->inDesignMode())
         return;
 
-    if (page->focusController()->advanceFocus(focusDirection, event))
+    if (page->focusController().advanceFocus(focusDirection, event))
         event->setDefaultHandled();
 }
 
@@ -3744,7 +3616,7 @@ void EventHandler::defaultTabEventHandler(KeyboardEvent* event)
     if (event->ctrlKey() || event->metaKey() || event->altGraphKey())
         return;
 
-    Page* page = m_frame->page();
+    Page* page = m_frame.page();
     if (!page)
         return;
     if (!page->tabKeyCyclesThroughElements())
@@ -3753,51 +3625,40 @@ void EventHandler::defaultTabEventHandler(KeyboardEvent* event)
     FocusDirection focusDirection = event->shiftKey() ? FocusDirectionBackward : FocusDirectionForward;
 
     // Tabs can be used in design mode editing.
-    if (m_frame->document()->inDesignMode())
+    if (m_frame.document()->inDesignMode())
         return;
 
-    if (page->focusController()->advanceFocus(focusDirection, event))
+    if (page->focusController().advanceFocus(focusDirection, event))
         event->setDefaultHandled();
 }
 
-void EventHandler::capsLockStateMayHaveChanged()
-{
-    Document* d = m_frame->document();
-    if (Element* element = d->focusedElement()) {
-        if (RenderObject* r = element->renderer()) {
-            if (r->isTextField())
-                toRenderTextControlSingleLine(r)->capsLockStateMayHaveChanged();
-        }
-    }
-}
-
 void EventHandler::sendScrollEvent()
 {
     setFrameWasScrolledByUser();
-    if (m_frame->view() && m_frame->document())
-        m_frame->document()->eventQueue()->enqueueOrDispatchScrollEvent(m_frame->document(), DocumentEventQueue::ScrollEventDocumentTarget);
+    if (m_frame.view() && m_frame.document())
+        m_frame.document()->eventQueue().enqueueOrDispatchScrollEvent(*m_frame.document());
 }
 
 void EventHandler::setFrameWasScrolledByUser()
 {
-    FrameView* v = m_frame->view();
+    FrameView* v = m_frame.view();
     if (v)
         v->setWasScrolledByUser(true);
 }
 
-bool EventHandler::passMousePressEventToScrollbar(MouseEventWithHitTestResults& mev, Scrollbar* scrollbar)
+bool EventHandler::passMousePressEventToScrollbar(MouseEventWithHitTestResults& mouseEvent, Scrollbar* scrollbar)
 {
     if (!scrollbar || !scrollbar->enabled())
         return false;
     setFrameWasScrolledByUser();
-    return scrollbar->mouseDown(mev.event());
+    return scrollbar->mouseDown(mouseEvent.event());
 }
 
 // If scrollbar (under mouse) is different from last, send a mouse exited. Set
-// last to scrollbar if setLast is true; else set last to 0.
+// last to scrollbar if setLast is true; else set last to nullptr.
 void EventHandler::updateLastScrollbarUnderMouse(Scrollbar* scrollbar, bool setLast)
 {
-    if (m_lastScrollbarUnderMouse != scrollbar) {
+    if (m_lastScrollbarUnderMouse.get() != scrollbar) {
         // Send mouse exited to the old scrollbar.
         if (m_lastScrollbarUnderMouse)
             m_lastScrollbarUnderMouse->mouseExited();
@@ -3806,12 +3667,14 @@ void EventHandler::updateLastScrollbarUnderMouse(Scrollbar* scrollbar, bool setL
         if (scrollbar && setLast)
             scrollbar->mouseEntered();
 
-        m_lastScrollbarUnderMouse = setLast ? scrollbar : 0;
+        if (setLast && scrollbar)
+            m_lastScrollbarUnderMouse = scrollbar->createWeakPtr();
+        else
+            m_lastScrollbarUnderMouse = nullptr;
     }
 }
 
-#if ENABLE(TOUCH_EVENTS)
-
+#if ENABLE(TOUCH_EVENTS) && !ENABLE(IOS_TOUCH_EVENTS)
 static const AtomicString& eventNameForTouchPointState(PlatformTouchPoint::State state)
 {
     switch (state) {
@@ -3831,12 +3694,13 @@ static const AtomicString& eventNameForTouchPointState(PlatformTouchPoint::State
     }
 }
 
-HitTestResult EventHandler::hitTestResultInFrame(Frame* frame, const LayoutPoint& point, HitTestRequest::HitTestRequestType hitType)
+static HitTestResult hitTestResultInFrame(Frame* frame, const LayoutPoint& point, HitTestRequest::HitTestRequestType hitType)
 {
     HitTestResult result(point);
 
     if (!frame || !frame->contentRenderer())
         return result;
+
     if (frame->view()) {
         IntRect rect = frame->view()->visibleContentRect();
         if (!rect.contains(roundedIntPoint(point)))
@@ -3857,11 +3721,11 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
 
     // A different view on the 'touches' list above, filtered and grouped by event target. Used for the
     // 'targetTouches' list in the JS event.
-    typedef HashMap<EventTarget*, RefPtr<TouchList> > TargetTouchesMap;
+    typedef HashMap<EventTarget*, RefPtr<TouchList>> TargetTouchesMap;
     TargetTouchesMap touchesByTarget;
 
     // Array of touches per state, used to assemble the 'changedTouches' list in the JS event.
-    typedef HashSet<RefPtr<EventTarget> > EventTargetSet;
+    typedef HashSet<RefPtr<EventTarget>> EventTargetSet;
     struct {
         // The touches corresponding to the particular change state this struct instance represents.
         RefPtr<TouchList> m_touches;
@@ -3871,21 +3735,18 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
 
     const Vector<PlatformTouchPoint>& points = event.touchPoints();
 
-    UserGestureIndicator gestureIndicator(DefinitelyProcessingUserGesture);
+    UserGestureIndicator gestureIndicator(DefinitelyProcessingUserGesture, m_frame.document());
 
-    unsigned i;
     bool freshTouchEvents = true;
     bool allTouchReleased = true;
-    for (i = 0; i < points.size(); ++i) {
-        const PlatformTouchPoint& point = points[i];
+    for (auto& point : points) {
         if (point.state() != PlatformTouchPoint::TouchPressed)
             freshTouchEvents = false;
         if (point.state() != PlatformTouchPoint::TouchReleased && point.state() != PlatformTouchPoint::TouchCancelled)
             allTouchReleased = false;
     }
 
-    for (i = 0; i < points.size(); ++i) {
-        const PlatformTouchPoint& point = points[i];
+    for (auto& point : points) {
         PlatformTouchPoint::State pointState = point.state();
         LayoutPoint pagePoint = documentPointForWindowPoint(m_frame, point.pos());
 
@@ -3926,39 +3787,34 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
                 result = hitTestResultAtPoint(pagePoint, hitType);
                 m_originatingTouchPointTargetKey = touchPointTargetKey;
             } else if (m_originatingTouchPointDocument.get() && m_originatingTouchPointDocument->frame()) {
-                LayoutPoint pagePointInOriginatingDocument = documentPointForWindowPoint(m_originatingTouchPointDocument->frame(), point.pos());
+                LayoutPoint pagePointInOriginatingDocument = documentPointForWindowPoint(*m_originatingTouchPointDocument->frame(), point.pos());
                 result = hitTestResultInFrame(m_originatingTouchPointDocument->frame(), pagePointInOriginatingDocument, hitType);
                 if (!result.innerNode())
                     continue;
             } else
                 continue;
 
-            // FIXME: Is the following code different from just calling innerElement?
-            Node* node = result.innerNode();
+            // FIXME: This code should use Element* instead of Node*.
+            Node* node = result.innerElement();
             ASSERT(node);
-            // Touch events should not go to text nodes
-            if (node->isTextNode())
-                node = EventPathWalker::parent(node);
 
-            if (InspectorInstrumentation::handleTouchEvent(m_frame->page(), node))
+            if (node && InspectorInstrumentation::handleTouchEvent(m_frame, *node))
                 return true;
 
-            Document* doc = node->document();
+            Document& doc = node->document();
             // Record the originating touch document even if it does not have a touch listener.
             if (freshTouchEvents) {
-                m_originatingTouchPointDocument = doc;
+                m_originatingTouchPointDocument = &doc;
                 freshTouchEvents = false;
             }
-            if (!doc)
-                continue;
-            if (!doc->hasTouchEventHandlers())
+            if (!doc.hasTouchEventHandlers())
                 continue;
             m_originatingTouchPointTargets.set(touchPointTargetKey, node);
             touchTarget = node;
         } else if (pointState == PlatformTouchPoint::TouchReleased || pointState == PlatformTouchPoint::TouchCancelled) {
             // No need to perform a hit-test since we only need to unset :hover and :active states.
             if (!shouldGesturesTriggerActive() && allTouchReleased)
-                m_frame->document()->updateHoverActiveState(hitType, 0);
+                m_frame.document()->updateHoverActiveState(hitType, 0);
             if (touchPointTargetKey == m_originatingTouchPointTargetKey)
                 m_originatingTouchPointTargetKey = 0;
 
@@ -3971,18 +3827,16 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
 
         if (!touchTarget.get())
             continue;
-        Document* doc = touchTarget->toNode()->document();
-        if (!doc)
-            continue;
-        if (!doc->hasTouchEventHandlers())
+        Document& doc = touchTarget->toNode()->document();
+        if (!doc.hasTouchEventHandlers())
             continue;
-        Frame* targetFrame = doc->frame();
+        Frame* targetFrame = doc.frame();
         if (!targetFrame)
             continue;
 
-        if (m_frame != targetFrame) {
+        if (&m_frame != targetFrame) {
             // pagePoint should always be relative to the target elements containing frame.
-            pagePoint = documentPointForWindowPoint(targetFrame, point.pos());
+            pagePoint = documentPointForWindowPoint(*targetFrame, point.pos());
         }
 
         float scaleFactor = targetFrame->pageZoomFactor() * targetFrame->frameScaleFactor();
@@ -4023,7 +3877,7 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
     }
     m_touchPressed = touches->length() > 0;
     if (allTouchReleased)
-        m_originatingTouchPointDocument.clear();
+        m_originatingTouchPointDocument = nullptr;
 
     // Now iterate the changedTouches list and m_targets within it, sending events to the targets as required.
     bool swallowedEvent = false;
@@ -4036,48 +3890,53 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
         bool isTouchCancelEvent = (state == PlatformTouchPoint::TouchCancelled);
         RefPtr<TouchList>& effectiveTouches(isTouchCancelEvent ? emptyList : touches);
         const AtomicString& stateName(eventNameForTouchPointState(static_cast<PlatformTouchPoint::State>(state)));
-        const EventTargetSet& targetsForState = changedTouches[state].m_targets;
 
-        for (EventTargetSet::const_iterator it = targetsForState.begin(); it != targetsForState.end(); ++it) {
-            EventTarget* touchEventTarget = it->get();
+        for (auto& taget : changedTouches[state].m_targets) {
+            EventTarget* touchEventTarget = taget.get();
             RefPtr<TouchList> targetTouches(isTouchCancelEvent ? emptyList : touchesByTarget.get(touchEventTarget));
             ASSERT(targetTouches);
 
-            RefPtr<TouchEvent> touchEvent =
+            Ref<TouchEvent> touchEvent =
                 TouchEvent::create(effectiveTouches.get(), targetTouches.get(), changedTouches[state].m_touches.get(),
-                                   stateName, touchEventTarget->toNode()->document()->defaultView(),
-                                   0, 0, 0, 0, event.ctrlKey(), event.altKey(), event.shiftKey(), event.metaKey());
-            touchEventTarget->toNode()->dispatchTouchEvent(touchEvent.get());
+                    stateName, touchEventTarget->toNode()->document().defaultView(),
+                    0, 0, 0, 0, event.ctrlKey(), event.altKey(), event.shiftKey(), event.metaKey());
+            touchEventTarget->toNode()->dispatchTouchEvent(touchEvent);
             swallowedEvent = swallowedEvent || touchEvent->defaultPrevented() || touchEvent->defaultHandled();
         }
     }
 
     return swallowedEvent;
 }
+#endif // ENABLE(TOUCH_EVENTS) && !ENABLE(IOS_TOUCH_EVENTS)
 
-bool EventHandler::dispatchSyntheticTouchEventIfEnabled(const PlatformMouseEvent& event)
+#if ENABLE(TOUCH_EVENTS)
+bool EventHandler::dispatchSyntheticTouchEventIfEnabled(const PlatformMouseEvent& platformMouseEvent)
 {
-    if (!m_frame || !m_frame->settings() || !m_frame->settings()->isTouchEventEmulationEnabled())
+#if ENABLE(IOS_TOUCH_EVENTS)
+    UNUSED_PARAM(platformMouseEvent);
+    return false;
+#else
+    if (!m_frame.settings().isTouchEventEmulationEnabled())
         return false;
 
-    PlatformEvent::Type eventType = event.type();
+    PlatformEvent::Type eventType = platformMouseEvent.type();
     if (eventType != PlatformEvent::MouseMoved && eventType != PlatformEvent::MousePressed && eventType != PlatformEvent::MouseReleased)
         return false;
 
     HitTestRequest request(HitTestRequest::Active | HitTestRequest::DisallowShadowContent);
-    MouseEventWithHitTestResults mev = prepareMouseEvent(request, event);
-    if (mev.scrollbar() || subframeForHitTestResult(mev))
+    MouseEventWithHitTestResults mouseEvent = prepareMouseEvent(request, platformMouseEvent);
+    if (mouseEvent.scrollbar() || subframeForHitTestResult(mouseEvent))
         return false;
 
     // The order is important. This check should follow the subframe test: http://webkit.org/b/111292.
     if (eventType == PlatformEvent::MouseMoved && !m_touchPressed)
         return true;
 
-    SyntheticSingleTouchEvent touchEvent(event);
+    SyntheticSingleTouchEvent touchEvent(platformMouseEvent);
     return handleTouchEvent(touchEvent);
-}
-
 #endif
+}
+#endif // ENABLE(TOUCH_EVENTS)
 
 void EventHandler::setLastKnownMousePosition(const PlatformMouseEvent& event)
 {
@@ -4086,4 +3945,9 @@ void EventHandler::setLastKnownMousePosition(const PlatformMouseEvent& event)
     m_lastKnownMouseGlobalPosition = event.globalPosition();
 }
 
+void EventHandler::setImmediateActionStage(ImmediateActionStage stage)
+{
+    m_immediateActionStage = stage;
+}
+
 } // namespace WebCore