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

Source/core/events/TextEvent.h

 /*
  * Copyright (C) 2007, 2008 Apple 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 43 matching lines @@
 
         bool isLineBreak() const { return m_inputType == TextEventInputLineBreak; }
         bool isComposition() const { return m_inputType == TextEventInputComposition; }
         bool isPaste() const { return m_inputType == TextEventInputPaste; }
         bool isDrop() const { return m_inputType == TextEventInputDrop; }
 
         bool shouldSmartReplace() const { return m_shouldSmartReplace; }
         bool shouldMatchStyle() const { return m_shouldMatchStyle; }
         DocumentFragment* pastingFragment() const { return m_pastingFragment.get(); }
 
+        virtual void trace(Visitor*) OVERRIDE;
+
     private:
         TextEvent();
 
         TextEvent(PassRefPtr<AbstractView>, const String& data, TextEventInputType = TextEventInputKeyboard);
         TextEvent(PassRefPtr<AbstractView>, const String& data, PassRefPtr<DocumentFragment>,
                   bool shouldSmartReplace, bool shouldMatchStyle);
 
         TextEventInputType m_inputType;
         String m_data;
 
         RefPtr<DocumentFragment> m_pastingFragment;
         bool m_shouldSmartReplace;
         bool m_shouldMatchStyle;
     };
 
 inline bool isTextEvent(const Event& event)
 {
     return event.type() == EventTypeNames::textInput && event.hasInterface(EventNames::TextEvent);
 }
 
 DEFINE_TYPE_CASTS(TextEvent, Event, event, isTextEvent(*event), isTextEvent(event));
 
 } // namespace WebCore
 
 #endif // TextEvent_h