Have content/ create and destroy its own threads.

content/browser/browser_main_loop.h

 // 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.
 
 #ifndef CONTENT_BROWSER_BROWSER_MAIN_LOOP_H_
 #define CONTENT_BROWSER_BROWSER_MAIN_LOOP_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
+#include "content/browser/browser_process_sub_thread.h"
 
 class CommandLine;
 class HighResolutionTimerManager;
 class MessageLoop;
 class SystemMessageWindowWin;
 
 namespace base {
 class SystemMonitor;
 }
 
 namespace net {
 class NetworkChangeNotifier;
 }
 
 namespace content {
 
 class BrowserMainParts;
+class BrowserShutdownImpl;
 class BrowserThreadImpl;
 struct MainFunctionParams;
 
 // Implements the main browser loop stages called from |BrowserMain()|.
 // See comments in browser_main_parts.h for additional info.
 class BrowserMainLoop {
  public:
   explicit BrowserMainLoop(const content::MainFunctionParams& parameters);
   virtual ~BrowserMainLoop();
 
   void Init();
 
   void EarlyInitialization();
   void InitializeToolkit();
   void MainMessageLoopStart();
   void RunMainMessageLoopParts(bool* completed_main_message_loop);
   void MainMessageLoopRun();
 
   int GetResultCode() const { return result_code_; }
 
  private:
+  // For ShutdownThreadsAndCleanUp.
+  friend class BrowserShutdownImpl;
+
+  // Performs the shutdown sequence, starting with PostMainMessageLoopRun
+  // through stopping threads to PostDestroyThreads.
+  void ShutdownThreadsAndCleanUp();
+
   void InitializeMainThread();
 
   // Members initialized on construction ---------------------------------------
   const content::MainFunctionParams& parameters_;
   const CommandLine& parsed_command_line_;
   int result_code_;
 
   // Members initialized in |MainMessageLoopStart()| ---------------------------
   scoped_ptr<MessageLoop> main_message_loop_;
   scoped_ptr<base::SystemMonitor> system_monitor_;
   scoped_ptr<HighResolutionTimerManager> hi_res_timer_manager_;
   scoped_ptr<net::NetworkChangeNotifier> network_change_notifier_;
 #if defined(OS_WIN)
   scoped_ptr<SystemMessageWindowWin> system_message_window_;
 #endif
 
   // Destroy parts_ before main_message_loop_ (required) and before other
   // classes constructed in content (but after main_thread_).
   scoped_ptr<BrowserMainParts> parts_;
 
   // Members initialized in |InitializeMainThread()| ---------------------------
   // This must get destroyed before other threads that are created in parts_.
   scoped_ptr<BrowserThreadImpl> main_thread_;
+  scoped_ptr<BrowserProcessSubThread> io_thread_;
+  scoped_ptr<BrowserProcessSubThread> file_thread_;
+  scoped_ptr<BrowserProcessSubThread> db_thread_;
+  scoped_ptr<BrowserProcessSubThread> process_launcher_thread_;
+  scoped_ptr<BrowserProcessSubThread> cache_thread_;
+#if defined(OS_CHROMEOS)
+  scoped_ptr<BrowserProcessSubThread> web_socket_proxy_thread_;
+#endif
 
   DISALLOW_COPY_AND_ASSIGN(BrowserMainLoop);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_BROWSER_MAIN_LOOP_H_