Fire overflowchanged events at raf timing

Source/core/dom/ScriptedAnimationController.h

 /*
  * Copyright (C) 2011 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 36 matching lines @@
     }
     ~ScriptedAnimationController();
     void clearDocumentPointer() { m_document = 0; }
 
     typedef int CallbackId;
 
     int registerCallback(PassRefPtr<RequestAnimationFrameCallback>);
     void cancelCallback(CallbackId);
     void serviceScriptedAnimations(double monotonicTimeNow);
 
-    void scheduleEvent(PassRefPtr<Event>);
+    void enqueueEvent(PassRefPtr<Event>);
+    void enqueuePerFrameEvent(PassRefPtr<Event>);
 
     void suspend();
     void resume();
 
 private:
     explicit ScriptedAnimationController(Document*);
 
     void scheduleAnimationIfNeeded();
 
     void dispatchEvents();
     void executeCallbacks(double monotonicTimeNow);
 
     typedef Vector<RefPtr<RequestAnimationFrameCallback> > CallbackList;
     CallbackList m_callbacks;
 
     Document* m_document;
     CallbackId m_nextCallbackId;
     int m_suspendCount;
     Vector<RefPtr<Event> > m_eventQueue;
-    ListHashSet<std::pair<const EventTarget*, const StringImpl*> > m_scheduledEventTargets;
+    ListHashSet<std::pair<const EventTarget*, const StringImpl*> > m_perFrameEvents;
 };
 
 }
 
 #endif // ScriptedAnimationController_h