ServiceWorker: Introduce ExtendableMessageEvent to replace MessageEvent

public/web/WebServiceWorkerContextClient.h

 /*
  * Copyright (C) 2013 Google 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.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 123 matching lines @@
     // ServiceWorker specific method. Called after SyncEvent (dispatched via
     // WebServiceWorkerContextProxy) is handled by the ServiceWorker's script
     // context.
     virtual void didHandleSyncEvent(int syncEventID, WebServiceWorkerEventResult result) { }
 
     // ServiceWorker specific method. Called after CrossOriginConnectEvent
     // (dispatched via WebServiceWorkerContextProxy) is handled by the
     // ServiceWorker's script context.
     virtual void didHandleCrossOriginConnectEvent(int connectEventID, bool acceptConnect) { }
 
+    // ServiceWorker specific method. Called after ExtendableMessageEvent
+    // (dispatched via WebServiceWorkerContextProxy) is handled by the
+    // ServiceWorker's script context.
+    virtual void didHandleMessageEvent(int messageEventID, WebServiceWorkerEventResult result) {}
+
     // Ownership of the returned object is transferred to the caller.
     // This is called on the main thread.
     virtual WebServiceWorkerNetworkProvider* createServiceWorkerNetworkProvider(WebDataSource*) { return nullptr; }
 
     // Ownership of the returned object is transferred to the caller.
     // This is called on the main thread.
     virtual WebServiceWorkerProvider* createServiceWorkerProvider() { return nullptr; }
 
     // Ownership of the passed callbacks is transferred to the callee, callee
     // should delete the callbacks after calling either onSuccess or onError.
@@ skipping 33 matching lines @@
     // should delete the callback after calling either onSuccess or onError.
     virtual void focus(const WebString& uuid, WebServiceWorkerClientCallbacks*) { BLINK_ASSERT_NOT_REACHED(); }
 
     // Ownership of the passed WebMessagePortChannel is NOT passed to the callee.
     virtual void stashMessagePort(WebMessagePortChannel*, const WebString& name) { BLINK_ASSERT_NOT_REACHED(); }
 };
 
 } // namespace blink
 
 #endif // WebServiceWorkerContextClient_h