Make Event RefCountedGarbageCollected and implement trace() methods to the Event hierarcy

Source/core/events/TouchEvent.cpp

 /*
  * 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 70 matching lines @@
 const AtomicString& TouchEvent::interfaceName() const
 {
     return EventNames::TouchEvent;
 }
 
 bool TouchEvent::isTouchEvent() const
 {
     return true;
 }
 
+void TouchEvent::trace(Visitor* visitor)
+{
+    MouseRelatedEvent::trace(visitor);
+}
+
 PassRefPtr<TouchEventDispatchMediator> TouchEventDispatchMediator::create(PassRefPtr<TouchEvent> touchEvent)
 {
     return adoptRef(new TouchEventDispatchMediator(touchEvent));
 }
 
 TouchEventDispatchMediator::TouchEventDispatchMediator(PassRefPtr<TouchEvent> touchEvent)
     : EventDispatchMediator(touchEvent)
 {
 }
 
 TouchEvent* TouchEventDispatchMediator::event() const
 {
     return toTouchEvent(EventDispatchMediator::event());
 }
 
 bool TouchEventDispatchMediator::dispatchEvent(EventDispatcher* dispatcher) const
 {
     event()->eventPath().adjustForTouchEvent(dispatcher->node(), *event());
     return dispatcher->dispatch();
 }
 
 } // namespace WebCore