ServiceWorker: Implement navigate() method in WindowClient (blink side).

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 169 matching lines @@
     virtual void skipWaiting(WebServiceWorkerSkipWaitingCallbacks*) { BLINK_ASSERT_NOT_REACHED(); }
 
     // Ownership of the passed callbacks is transferred to the callee, callee
     // should delete the callbacks after run.
     virtual void claim(WebServiceWorkerClientsClaimCallbacks*) { BLINK_ASSERT_NOT_REACHED(); }
 
     // Ownership of the passed callbacks is transferred to the callee, callee
     // 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 callbacks is transferred to the callee, callee
+    // should delete the callbacks after calling either onSuccess or onError.
+    // WebServiceWorkerClientInfo and WebServiceWorkerError ownerships are
+    // passed to the WebServiceWorkerClientsCallbacks implementation.
+    virtual void navigate(const WebString& uuid, const WebURL&, 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