Delete desktop/shell instance correctly when chrome is shutting down

ui/aura_shell/shell.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 "ui/aura_shell/shell.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "ui/aura/aura_switches.h"
 #include "ui/aura/client/aura_constants.h"
@@ skipping 137 matching lines @@
   return instance_;
 }
 
 // static
 Shell* Shell::GetInstance() {
   DCHECK(instance_);
   return instance_;
 }
 
 // static
-void Shell::DeleteInstanceForTesting() {
+void Shell::DeleteInstance() {
   delete instance_;
   instance_ = NULL;
 }
 
 void Shell::Init() {
   aura::Desktop* desktop_window = aura::Desktop::GetInstance();
   desktop_window->SetCursor(aura::kCursorPointer);
 
   aura::Window::Windows containers;
   CreateSpecialContainers(&containers);
@@ skipping 100 matching lines @@
       new internal::WorkspaceController(default_container));
   workspace_controller_->SetLauncherModel(launcher_->model());
   default_container->SetEventFilter(
       new internal::DefaultContainerEventFilter(default_container));
   default_container->SetLayoutManager(
       new internal::DefaultContainerLayoutManager(
           workspace_controller_->workspace_manager()));
 }
 
 }  // namespace aura_shell