Remove custom code for MessageEvent.ports getter

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 70 matching lines @@
         return adoptRef(new MessageEvent(type, initializer));
     }
     virtual ~MessageEvent();
 
     void initMessageEvent(const AtomicString& type, bool canBubble, bool cancelable, const ScriptValue& data, const String& origin, const String& lastEventId, DOMWindow* source, PassOwnPtr<MessagePortArray>);
     void initMessageEvent(const AtomicString& type, bool canBubble, bool cancelable, PassRefPtr<SerializedScriptValue> data, const String& origin, const String& lastEventId, DOMWindow* source, PassOwnPtr<MessagePortArray>);
 
     const String& origin() const { return m_origin; }
     const String& lastEventId() const { return m_lastEventId; }
     DOMWindow* source() const { return m_source.get(); }
-    MessagePortArray* ports() const { return m_ports.get(); }
+    MessagePortArray ports() const { return m_ports ? *m_ports : MessagePortArray(); }
 
     virtual const AtomicString& interfaceName() const;
 
     enum DataType {
         DataTypeScriptValue,
         DataTypeSerializedScriptValue,
         DataTypeString,
         DataTypeBlob,
         DataTypeArrayBuffer
     };
@@ skipping 22 matching lines @@
     RefPtr<ArrayBuffer> m_dataAsArrayBuffer;
     String m_origin;
     String m_lastEventId;
     RefPtr<DOMWindow> m_source;
     OwnPtr<MessagePortArray> m_ports;
 };
 
 } // namespace WebCore
 
 #endif // MessageEvent_h