Simplify WebServiceWorker{Registration}Proxy interfaces.

public/platform/WebServiceWorkerProxy.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WebServiceWorkerProxy_h
 #define WebServiceWorkerProxy_h
 
-#include "WebCommon.h"
-
 namespace blink {
 
-class ServiceWorker;
-
 // A proxy interface, passed via WebServiceWorker.setProxy() from blink to
 // the embedder, to talk to the ServiceWorker object from embedder.
 class WebServiceWorkerProxy {
 public:
-    WebServiceWorkerProxy() : m_private(0) { }
-    virtual ~WebServiceWorkerProxy() { }
-
     // Returns true if the proxy is ready to be notified of service worker state
     // changes. It may not be if it's waiting for the registration promise to
     // resolve, while the browser side has registered and is proceeding to
     // install and activate the worker.
     virtual bool isReady() = 0;
 
     // Notifies the proxy that the service worker state changed. The new state
     // should be accessible via WebServiceWorker.state().
     virtual void dispatchStateChangeEvent() = 0;
 
-#if INSIDE_BLINK
-    BLINK_PLATFORM_EXPORT WebServiceWorkerProxy(ServiceWorker*);
-    BLINK_PLATFORM_EXPORT ServiceWorker* unwrap() const;
-#endif
-
 protected:
-    ServiceWorker* m_private;
+    virtual ~WebServiceWorkerProxy() { }
 };
 
 } // namespace blink
 
 #endif // WebServiceWorkerProxy_h