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

content/browser/service_worker/service_worker_version.cc

 // 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.
 
 #include "content/browser/service_worker/service_worker_version.h"
 
 #include "base/command_line.h"
 #include "base/stl_util.h"
 #include "base/strings/string16.h"
 #include "content/browser/service_worker/embedded_worker_instance.h"
@@ skipping 271 matching lines @@
                    base::Bind(&self::DispatchActivateEventAfterStartWorker,
                               weak_factory_.GetWeakPtr(),
                               callback)));
   } else {
     DispatchActivateEventAfterStartWorker(callback);
   }
 }
 
 void ServiceWorkerVersion::DispatchFetchEvent(
     const ServiceWorkerFetchRequest& request,
-    const FetchCallback& callback) {
+    const base::Closure& prepare_callback,
+    const FetchCallback& fetch_callback) {
   DCHECK_EQ(ACTIVATED, status()) << status();
 
   if (running_status() != RUNNING) {
     // Schedule calling this method after starting the worker.
     StartWorker(base::Bind(&RunTaskAfterStartWorker,
                            weak_factory_.GetWeakPtr(),
-                           base::Bind(&RunErrorFetchCallback, callback),
+                           base::Bind(&RunErrorFetchCallback, fetch_callback),
                            base::Bind(&self::DispatchFetchEvent,
                                       weak_factory_.GetWeakPtr(),
-                                      request, callback)));
+                                      request,
+                                      prepare_callback,
+                                      fetch_callback)));
     return;
   }
 
-  int request_id = fetch_callbacks_.Add(new FetchCallback(callback));
+  prepare_callback.Run();
+
+  int request_id = fetch_callbacks_.Add(new FetchCallback(fetch_callback));
   ServiceWorkerStatusCode status = embedded_worker_->SendMessage(
       ServiceWorkerMsg_FetchEvent(request_id, request));
   if (status != SERVICE_WORKER_OK) {
     fetch_callbacks_.Remove(request_id);
     RunSoon(base::Bind(&RunErrorFetchCallback,
-                       callback,
+                       fetch_callback,
                        SERVICE_WORKER_ERROR_FAILED));
   }
 }
 
 void ServiceWorkerVersion::DispatchSyncEvent(const StatusCallback& callback) {
   DCHECK_EQ(ACTIVATED, status()) << status();
 
   if (!CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableServiceWorkerSync)) {
     callback.Run(SERVICE_WORKER_ERROR_ABORT);
@@ skipping 369 matching lines @@
   SetStatus(REDUNDANT);
   StopWorker(base::Bind(&ServiceWorkerUtils::NoOpStatusCallback));
   if (!context_)
     return;
   std::vector<ServiceWorkerDatabase::ResourceRecord> resources;
   script_cache_map_.GetResources(&resources);
   context_->storage()->PurgeResources(resources);
 }
 
 }  // namespace content