Reduce repetitive EventTarget subclassing

Source/modules/mediasource/SourceBufferList.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * 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
@@ skipping 72 matching lines @@
 const AtomicString& SourceBufferList::interfaceName() const
 {
     return eventNames().interfaceForSourceBufferList;
 }
 
 ScriptExecutionContext* SourceBufferList::scriptExecutionContext() const
 {
     return m_scriptExecutionContext;
 }
 
-EventTargetData* SourceBufferList::eventTargetData()
-{
-    return &m_eventTargetData;
-}
-
-EventTargetData* SourceBufferList::ensureEventTargetData()
-{
-    return &m_eventTargetData;
-}
-
 } // namespace WebCore