change the way windows are parented when their parent is set to NULL.

ui/aura_shell/aura_shell_main.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 "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/i18n/icu_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "ui/aura/desktop.h"
+#include "ui/aura_shell/shell.h"
 #include "ui/aura_shell/shell_factory.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_paths.h"
 
 int main(int argc, char** argv) {
   CommandLine::Init(argc, argv);
 
   // The exit manager is in charge of calling the dtors of singleton objects.
   base::AtExitManager exit_manager;
 
   ui::RegisterPathProvider();
   icu_util::Initialize();
   ResourceBundle::InitSharedInstance("en-US");
 
   // Create the message-loop here before creating the desktop.
   MessageLoop message_loop(MessageLoop::TYPE_UI);
 
-  aura_shell::InitDesktopWindow();
+  aura_shell::Shell shell;
+  shell.Init();
 
   aura_shell::examples::InitWindowTypeLauncher();
 
   aura::Desktop::GetInstance()->Run();
 
   delete aura::Desktop::GetInstance();
 
   return 0;
 }