First step to refactor ServiceWorkerVersion to make event dispatching more modular.

content/browser/service_worker/service_worker_test_utils.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 CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_TEST_UTILS_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_TEST_UTILS_H_
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace content {
 
 template <typename Arg>
 void ReceiveResult(BrowserThread::ID run_quit_thread,
                    const base::Closure& quit,
                    Arg* out, Arg actual) {
   *out = actual;
   if (!quit.is_null())
     BrowserThread::PostTask(run_quit_thread, FROM_HERE, quit);
 }
 
 template <typename Arg> base::Callback<void(Arg)>
 CreateReceiver(BrowserThread::ID run_quit_thread,
                const base::Closure& quit, Arg* out) {
   return base::Bind(&ReceiveResult<Arg>, run_quit_thread, quit, out);
 }
 
-template <typename Arg> base::Callback<void(Arg)>
-CreateReceiverOnCurrentThread(Arg* out) {
+template <typename Arg>
+base::Callback<void(Arg)> CreateReceiverOnCurrentThread(
+    Arg* out,
+    const base::Closure& quit = base::Closure()) {
   BrowserThread::ID id;
   bool ret = BrowserThread::GetCurrentThreadIdentifier(&id);
   DCHECK(ret);
-  return base::Bind(&ReceiveResult<Arg>, id, base::Closure(), out);
+  return base::Bind(&ReceiveResult<Arg>, id, quit, out);
 }
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_TEST_UTILS_H_