Virtualize EventDispatchMediator creation and cleanup calling.

Source/core/events/TouchEvent.h

 /*
  * Copyright 2008, The Android Open Source Project
  * Copyright (C) 2012 Research In Motion Limited. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *  * Redistributions in binary form must reproduce the above copyright
@@ skipping 58 matching lines @@
     void setChangedTouches(PassRefPtrWillBeRawPtr<TouchList> changedTouches) { m_changedTouches = changedTouches; }
 
     bool causesScrollingIfUncanceled() const { return m_causesScrollingIfUncanceled; }
 
     bool isTouchEvent() const override;
 
     const AtomicString& interfaceName() const override;
 
     void preventDefault() override;
 
+    PassRefPtrWillBeRawPtr<EventDispatchMediator> createMediator() override;
+
     DECLARE_VIRTUAL_TRACE();
 
 private:
     TouchEvent();
     TouchEvent(TouchList* touches, TouchList* targetTouches,
             TouchList* changedTouches, const AtomicString& type,
             PassRefPtrWillBeRawPtr<AbstractView>,
             bool ctrlKey, bool altKey, bool shiftKey, bool metaKey, bool cancelable, bool causesScrollingIfUncanceled,
             double uiCreateTime = 0);
 
@@ skipping 11 matching lines @@
     explicit TouchEventDispatchMediator(PassRefPtrWillBeRawPtr<TouchEvent>);
     TouchEvent& event() const;
     bool dispatchEvent(EventDispatcher&) const override;
 };
 
 DEFINE_EVENT_TYPE_CASTS(TouchEvent);
 
 } // namespace blink
 
 #endif // TouchEvent_h