Simplify WebServiceWorker{Registration}Proxy interfaces.

public/platform/WebServiceWorkerRegistrationProxy.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 WebServiceWorkerRegistrationProxy_h
 #define WebServiceWorkerRegistrationProxy_h
 
-#if INSIDE_BLINK
-#include "platform/heap/Handle.h"
-#endif
-#include "public/platform/WebCommon.h"
-
 namespace blink {
 
-class ServiceWorkerRegistration;
 class WebServiceWorker;
 
 // A proxy interface, passed via WebServiceWorkerRegistration.setProxy() from
 // blink to the embedder, to talk to the ServiceWorkerRegistration object from
 // embedder.
 class WebServiceWorkerRegistrationProxy {
 public:
-    WebServiceWorkerRegistrationProxy() : m_private(0) { }
-    virtual ~WebServiceWorkerRegistrationProxy() { }
-
     // Notifies that the registration entered the installation process.
     // The installing worker should be accessible via
     // WebServiceWorkerRegistration.installing.
     virtual void dispatchUpdateFoundEvent() = 0;
 
     virtual void setInstalling(WebServiceWorker*) = 0;
     virtual void setWaiting(WebServiceWorker*) = 0;
     virtual void setActive(WebServiceWorker*) = 0;
 
-#if INSIDE_BLINK
-    BLINK_PLATFORM_EXPORT WebServiceWorkerRegistrationProxy(ServiceWorkerRegistration*);
-    BLINK_PLATFORM_EXPORT operator ServiceWorkerRegistration*() const;
-#endif
-
 protected:
-#if INSIDE_BLINK
-    // This is a back pointer to |this| object.
-    // The ServiceWorkerRegistration inherits from this WebServiceWorkerRegistrationProxy.
-    GC_PLUGIN_IGNORE("crbug.com/410257")
-#endif
-    ServiceWorkerRegistration* m_private;
+    virtual ~WebServiceWorkerRegistrationProxy() { }
 };
 
 } // namespace blink
 
 #endif // WebServiceWorkerRegistrationProxy_h