Have content/ create and destroy its own threads.

chrome/browser/ui/gtk/constrained_window_gtk.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/gtk/constrained_window_gtk.h"
 
 #include <gdk/gdkkeysyms.h>
 
 #include "base/bind.h"
+#include "base/message_loop.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/constrained_window_tab_helper.h"
 #include "chrome/browser/ui/gtk/gtk_util.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/public/browser/browser_thread.h"
 #include "ui/base/gtk/gtk_hig_constants.h"
 
 #if defined(TOUCH_UI)
 #include "chrome/browser/ui/views/tab_contents/tab_contents_view_views.h"
@@ skipping 138 matching lines @@
 }
 
 void ConstrainedWindowGtk::OnHierarchyChanged(GtkWidget* sender,
                                               GtkWidget* previous_toplevel) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (!GTK_WIDGET_TOPLEVEL(gtk_widget_get_toplevel(widget())))
     return;
 
   FocusConstrainedWindow();
 }