Start to implement FetchEvent for ServiceWorker

Source/modules/serviceworkers/ServiceWorkerGlobalScopeClient.h

 /*
  * Copyright (C) 2014 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 20 matching lines @@
 #ifndef ServiceWorkerGlobalScopeClient_h
 #define ServiceWorkerGlobalScopeClient_h
 
 #include "core/workers/WorkerClients.h"
 #include "wtf/Forward.h"
 #include "wtf/Noncopyable.h"
 
 namespace WebCore {
 
 class ExecutionContext;
+class Response;
 class WorkerClients;
 
 class ServiceWorkerGlobalScopeClient : public Supplement<WorkerClients> {
     WTF_MAKE_NONCOPYABLE(ServiceWorkerGlobalScopeClient);
 public:
     virtual ~ServiceWorkerGlobalScopeClient() { }
 
     virtual void didHandleInstallEvent(int installEventID) = 0;
+    // A null response means no valid response was provided by the service worker, so fallback to native.
+    virtual void didHandleFetchEvent(int fetchEventID, PassRefPtr<Response> = nullptr) = 0;
 
     static const char* supplementName();
     static ServiceWorkerGlobalScopeClient* from(ExecutionContext*);
 
 protected:
     ServiceWorkerGlobalScopeClient() { }
 };
 
 void provideServiceWorkerGlobalScopeClientToWorker(WorkerClients*, PassOwnPtr<ServiceWorkerGlobalScopeClient>);
 
 } // namespace WebCore
 
 #endif // ServiceWorkerGlobalScopeClient_h