Reduce repetitive EventTarget subclassing

Source/core/xml/XMLHttpRequestEventTarget.h

 /*
  * Copyright (C) 2013 Samsung Electronics. 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 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef XMLHttpRequestEventTarget_h
 #define XMLHttpRequestEventTarget_h
 
 #include "core/events/EventTarget.h"
 
 namespace WebCore {
 
-class XMLHttpRequestEventTarget : public EventTarget {
+class XMLHttpRequestEventTarget : public EventTargetWithInlineData {
 public:
     DEFINE_ATTRIBUTE_EVENT_LISTENER(abort);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(error);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(load);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(loadend);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(loadstart);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(progress);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(timeout);
-
-protected:
-    virtual EventTargetData* eventTargetData() OVERRIDE { return &m_eventTargetData; }
-    virtual EventTargetData* ensureEventTargetData() OVERRIDE { return &m_eventTargetData; }
-
-private:
-    EventTargetData m_eventTargetData;
 };
 
 } // namespace WebCore
 
 #endif // XMLHttpRequestEventTarget_h