Reduce repetitive EventTarget subclassing

Source/core/html/track/TrackBase.cpp

 /*
  * Copyright (C) 2011 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 31 matching lines @@
 const AtomicString& TrackBase::interfaceName() const
 {
     return eventNames().interfaceForTextTrack;
 }
 
 ScriptExecutionContext* TrackBase::scriptExecutionContext() const
 {
     return m_scriptExecutionContext;
 }
 
-EventTargetData* TrackBase::eventTargetData()
-{
-    return &m_eventTargetData;
-}
-
-EventTargetData* TrackBase::ensureEventTargetData()
-{
-    return &m_eventTargetData;
-}
-
 } // namespace WebCore