Have content/ create and destroy its own threads.

chrome/browser/browser_shutdown.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 CHROME_BROWSER_BROWSER_SHUTDOWN_H__
 #define CHROME_BROWSER_BROWSER_SHUTDOWN_H__
 #pragma once
 
 class PrefService;
 
@@ skipping 16 matching lines @@
 
 void RegisterPrefs(PrefService* local_state);
 
 // Called when the browser starts shutting down so that we can measure shutdown
 // time.
 void OnShutdownStarting(ShutdownType type);
 
 // Get the current shutdown type.
 ShutdownType GetShutdownType();
 
+// Performs the shutdown tasks that need to be done before
+// BrowserProcess and the various threads go away.
+//
+// Returns true if the session should be restarted.
+bool ShutdownPreThreadsStop();
+
+// Performs the remaining shutdown tasks after all threads but the
+// main thread have been stopped.  This includes deleting g_browser_process.
+//
 // Invoked in two ways:
 // . When the last browser has been deleted and the message loop has finished
 //   running.
 // . When ChromeFrame::EndSession is invoked and we need to do cleanup.

[robertshield, 2011/11/14 04:15:55]

This second bullet in this old comment looks out of date. Either
BrowserProcessImpl::EndSession() or BrowserList::TimeLimitedSessionEnding() are
probably what are being referred to.

 //   NOTE: in this case the message loop is still running, but will die soon
 //         after this returns.
-void Shutdown();
+//
+// The provided parameter indicates whether a preference to restart
+// the session was present.
+void ShutdownPostThreadsStop(bool restart_last_session);
 
 // Called at startup to create a histogram from our previous shutdown time.
 void ReadLastShutdownInfo();
 
 // There are various situations where the browser process should continue to
 // run after the last browser window has closed - the Mac always continues
 // running until the user explicitly quits, and on Windows/Linux the application
 // should not shutdown when the last browser window closes if there are any
 // BackgroundContents running.
 // When the user explicitly chooses to shutdown the app (via the "Exit" or
@@ skipping 17 matching lines @@
 // explicitly close the browser windows, which can lead to conditions which
 // would fail checks.
 bool ShuttingDownWithoutClosingBrowsers();
 
 // Sets the ShuttingDownWithoutClosingBrowsers flag.
 void SetShuttingDownWithoutClosingBrowsers(bool without_close);
 
 }  // namespace browser_shutdown
 
 #endif  // CHROME_BROWSER_BROWSER_SHUTDOWN_H__