[WIP] Use the flat tree for hover handling.

third_party/WebKit/Source/core/input/EventHandler.cpp

Index: third_party/WebKit/Source/core/input/EventHandler.cpp
diff --git a/third_party/WebKit/Source/core/input/EventHandler.cpp b/third_party/WebKit/Source/core/input/EventHandler.cpp
index 7d8aeabcfe489045402819de9ffbd4571fd90690..d6cc2657b2415f5fccef1aef27212287f5db12a1 100644
--- a/third_party/WebKit/Source/core/input/EventHandler.cpp
+++ b/third_party/WebKit/Source/core/input/EventHandler.cpp
@@ -1473,7 +1473,7 @@ void EventHandler::updateGestureHoverActiveState(const HitTestRequest& request,
                                   : nullptr;
   }
 
-  Node* oldHoverNodeInCurDoc = m_frame->document()->hoverNode();
+  Node* oldHoverNodeInCurDoc = m_frame->document()->hoverElement();
   Node* newInnermostHoverNode = innerElement;
 
   if (newInnermostHoverNode != oldHoverNodeInCurDoc) {
@@ -1499,7 +1499,7 @@ void EventHandler::updateGestureHoverActiveState(const HitTestRequest& request,
       if (!doc)
         break;
 
-      oldHoverNodeInCurDoc = doc->hoverNode();
+      oldHoverNodeInCurDoc = doc->hoverElement();
       // If the old hovered frame is different from the new hovered frame.
       // we should clear the old hovered node from the old hovered frame.
       if (newHoverFrame != oldHoverFrame)