Start/stop WebKitThread from BrowserMainLoop like other BrowserThreads.

chrome/browser/browser_process_impl.cc

 // Copyright (c) 2011 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 "chrome/browser/browser_process_impl.h"
 
 #include <map>
 #include <set>
 #include <vector>
 
@@ skipping 255 matching lines @@
       // Clean up state that lives on or uses the file_thread_ before
       // it goes away.
       if (resource_dispatcher_host_.get()) {
         resource_dispatcher_host()->download_file_manager()->Shutdown();
         resource_dispatcher_host()->save_file_manager()->Shutdown();
       }
       break;
     case BrowserThread::WEBKIT:
       // Need to destroy ResourceDispatcherHost before PluginService
       // and SafeBrowsingService, since it caches a pointer to
-      // it. This also causes the webkit thread to terminate (which is
-      // still the responsibility of the embedder, not of the content
-      // framework).
+      // it.
       resource_dispatcher_host_.reset();
       break;
     default:
       break;
   }
 }
 
 void BrowserProcessImpl::PostStopThread(BrowserThread::ID thread_id) {
   switch (thread_id) {
     case BrowserThread::FILE:
@@ skipping 719 matching lines @@
 }
 
 void BrowserProcessImpl::OnAutoupdateTimer() {
   if (CanAutorestartForUpdate()) {
     DLOG(WARNING) << "Detected update.  Restarting browser.";
     RestartBackgroundInstance();
   }
 }
 
 #endif  // (defined(OS_WIN) || defined(OS_LINUX)) && !defined(OS_CHROMEOS)