Have content/ create and destroy its own threads.

chrome/browser/ui/browser_list.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/ui/browser_list.h"
 
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "build/build_config.h"
@@ skipping 550 matching lines @@
   BrowserList::CloseAllBrowsers();
 
   // Send out notification. This is used during testing so that the test harness
   // can properly shutdown before we exit.
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_SESSION_END,
       content::NotificationService::AllSources(),
       content::NotificationService::NoDetails());
 
   // And shutdown.
-  browser_shutdown::Shutdown();
+  // TODO(joi): DO NOT SUBMIT - just seeing what breaks.
+  //browser_shutdown::Shutdown();
 }
 
 // static
 void BrowserList::SessionEnding() {
   TimeLimitedSessionEnding();
 
 #if defined(OS_WIN)
   // At this point the message loop is still running yet we've shut everything
   // down. If any messages are processed we'll likely crash. Exit now.
   ExitProcess(content::RESULT_CODE_NORMAL_EXIT);
@@ skipping 233 matching lines @@
   // If no more TabContents from Browsers, check the BackgroundPrintingManager.
   while (bg_printing_iterator_ != GetBackgroundPrintingManager()->end()) {
     cur_ = *bg_printing_iterator_;
     CHECK(cur_);
     ++bg_printing_iterator_;
     return;
   }
   // Reached the end - no more TabContents.
   cur_ = NULL;
 }