MessageEvent constructor should accept a MessagePort as source

Source/core/dom/MessageEvent.h

 /*
  * Copyright (C) 2007 Henry Mason (hmason@mac.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 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
@@ skipping 25 matching lines @@
 #include "core/page/DOMWindow.h"
 #include "wtf/ArrayBuffer.h"
 
 namespace WebCore {
 
 struct MessageEventInit : public EventInit {
     MessageEventInit();
 
     String origin;
     String lastEventId;
-    RefPtr<DOMWindow> source;
+    RefPtr<EventTarget> source;
     MessagePortArray ports;
 };
 
 class MessageEvent : public Event {
 public:
     static PassRefPtr<MessageEvent> create()
     {
         return adoptRef(new MessageEvent);
     }
     static PassRefPtr<MessageEvent> create(PassOwnPtr<MessagePortArray> ports, const String& origin = "", const String& lastEventId = "", PassRefPtr<EventTarget> source = 0)
@@ skipping 68 matching lines @@
     RefPtr<ArrayBuffer> m_dataAsArrayBuffer;
     String m_origin;
     String m_lastEventId;
     RefPtr<EventTarget> m_source;
     OwnPtr<MessagePortArray> m_ports;
 };
 
 } // namespace WebCore
 
 #endif // MessageEvent_h