ServiceWorker: Add prepare_callback in DispatchFetchEvent to notify the end of SW preparation.

content/browser/service_worker/service_worker_version.h

 // Copyright 2013 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 CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_VERSION_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_VERSION_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 162 matching lines @@
   // Upon completion, the version's status will be changed to ACTIVATED
   // on success, or back to INSTALLED on failure.
   void DispatchActivateEvent(const StatusCallback& callback);
 
   // Sends fetch event to the associated embedded worker and calls
   // |callback| with the response from the worker.
   //
   // This must be called when the status() is ACTIVATED. Calling this in other
   // statuses will result in an error SERVICE_WORKER_ERROR_FAILED.
   void DispatchFetchEvent(const ServiceWorkerFetchRequest& request,
-                          const FetchCallback& callback);
+                          const base::Closure& prepare_callback,
+                          const FetchCallback& fetch_callback);
 
   // Sends sync event to the associated embedded worker and asynchronously calls
   // |callback| when it errors out or it gets response from the worker to notify
   // completion.
   //
   // This must be called when the status() is ACTIVATED.
   void DispatchSyncEvent(const StatusCallback& callback);
 
   // Sends push event to the associated embedded worker and asynchronously calls
   // |callback| when it errors out or it gets response from the worker to notify
@@ skipping 113 matching lines @@
   bool is_doomed_;
 
   base::WeakPtrFactory<ServiceWorkerVersion> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerVersion);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_VERSION_H_