Remove unnecessary Document.h includes in .cpp files

Source/core/dom/MessagePort.cpp

 /*
  * Copyright (C) 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 12 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
 
 #include "config.h"
 #include "core/dom/MessagePort.h"
 
 #include "bindings/v8/ExceptionState.h"
 #include "bindings/v8/ExceptionStatePlaceholder.h"
 #include "bindings/v8/SerializedScriptValue.h"
-#include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/events/MessageEvent.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/workers/WorkerGlobalScope.h"
 #include "public/platform/WebString.h"
 #include "wtf/Functional.h"
 #include "wtf/text/AtomicString.h"
 
 namespace WebCore {
@@ skipping 206 matching lines @@
     OwnPtrWillBeRawPtr<MessagePortArray> portArray = adoptPtrWillBeNoop(new MessagePortArray(channels->size()));
     for (unsigned i = 0; i < channels->size(); ++i) {
         RefPtrWillBeRawPtr<MessagePort> port = MessagePort::create(context);
         port->entangle((*channels)[i].release());
         (*portArray)[i] = port.release();
     }
     return portArray.release();
 }
 
 } // namespace WebCore