Delete desktop/shell instance correctly when chrome is shutting down

ui/aura_shell/shell.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 UI_AURA_SHELL_SHELL_H_
 #define UI_AURA_SHELL_SHELL_H_
 #pragma once
 
 #include <utility>
 #include <vector>
@@ skipping 36 matching lines @@
   // Upon creation, the Shell sets itself as the Desktop's delegate, which takes
   // ownership of the Shell.
 
   // A shell must be explicitly created so that it can call |Init()| with the
   // delegate set. |delegate| can be NULL (if not required for initialization).
   static Shell* CreateInstance(ShellDelegate* delegate);
 
   // Should never be called before |CreateInstance()|.
   static Shell* GetInstance();
 
-  static void DeleteInstanceForTesting();
+  static void DeleteInstance();
 
   aura::Window* GetContainer(int container_id);
   const aura::Window* GetContainer(int container_id) const;
 
   // Adds or removes |filter| from the DesktopEventFilter.
   void AddDesktopEventFilter(aura::EventFilter* filter);
   void RemoveDesktopEventFilter(aura::EventFilter* filter);
 
   // Toggles between overview mode and normal mode.
   void ToggleOverview();
@@ skipping 51 matching lines @@
   scoped_ptr<internal::ShellAcceleratorFilter> accelerator_filter_;
 
   scoped_ptr<ShellTooltipManager> tooltip_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(Shell);
 };
 
 }  // namespace aura_shell
 
 #endif  // UI_AURA_SHELL_SHELL_H_