Inherit EventTarget interface instead of duplicating its code

Source/core/page/Performance.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel 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.
@@ skipping 33 matching lines @@
 #include <wtf/RefPtr.h>
 #include <wtf/text/WTFString.h>
 
 namespace WebCore {
 
 class Document;
 class ResourceRequest;
 class ResourceResponse;
 class UserTiming;
 
-class Performance : public ScriptWrappable, public RefCounted<Performance>, public DOMWindowProperty, public EventTarget {
+class Performance : public EventTarget, public ScriptWrappable, public RefCounted<Performance>, public DOMWindowProperty {
 public:
     static PassRefPtr<Performance> create(Frame* frame) { return adoptRef(new Performance(frame)); }
     ~Performance();
 
     virtual const AtomicString& interfaceName() const;
     virtual ScriptExecutionContext* scriptExecutionContext() const;
 
     PassRefPtr<MemoryInfo> memory() const;
     PerformanceNavigation* navigation() const;
     PerformanceTiming* timing() const;
@@ skipping 35 matching lines @@
 
     Vector<RefPtr<PerformanceEntry> > m_resourceTimingBuffer;
     unsigned m_resourceTimingBufferSize;
 
     RefPtr<UserTiming> m_userTiming;
 };
 
 }
 
 #endif // Performance_h