Reduce repetitive EventTarget subclassing

Source/modules/mediastream/MediaStreamTrack.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  * Copyright (C) 2011 Ericsson AB. 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
@@ skipping 172 matching lines @@
 const AtomicString& MediaStreamTrack::interfaceName() const
 {
     return eventNames().interfaceForMediaStreamTrack;
 }
 
 ScriptExecutionContext* MediaStreamTrack::scriptExecutionContext() const
 {
     return ActiveDOMObject::scriptExecutionContext();
 }
 
-EventTargetData* MediaStreamTrack::eventTargetData()
-{
-    return &m_eventTargetData;
-}
-
-EventTargetData* MediaStreamTrack::ensureEventTargetData()
-{
-    return &m_eventTargetData;
-}
-
 } // namespace WebCore