Remove the singleton instance get/delete methods from RootWindow (yay)

ui/aura/demo/demo_main.cc

 // Copyright (c) 2012 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 "third_party/skia/include/core/SkXfermode.h"
@@ skipping 70 matching lines @@
   base::AtExitManager exit_manager;
 
   ui::RegisterPathProvider();
   icu_util::Initialize();
   ResourceBundle::InitSharedInstanceWithLocale("en-US");
 
   // Create the message-loop here before creating the root window.
   MessageLoop message_loop(MessageLoop::TYPE_UI);
   ui::CompositorTestSupport::Initialize();
 
-  aura::RootWindow::GetInstance();
+  scoped_ptr<aura::RootWindow> root_window(new aura::RootWindow);
 
   // Create a hierarchy of test windows.
   DemoWindowDelegate window_delegate1(SK_ColorBLUE);
   aura::Window window1(&window_delegate1);
   window1.set_id(1);
   window1.Init(ui::Layer::LAYER_TEXTURED);
   window1.SetBounds(gfx::Rect(100, 100, 400, 400));
   window1.Show();
   window1.SetParent(NULL);
 
   DemoWindowDelegate window_delegate2(SK_ColorRED);
   aura::Window window2(&window_delegate2);
   window2.set_id(2);
   window2.Init(ui::Layer::LAYER_TEXTURED);
   window2.SetBounds(gfx::Rect(200, 200, 350, 350));
   window2.Show();
   window2.SetParent(NULL);
 
   DemoWindowDelegate window_delegate3(SK_ColorGREEN);
   aura::Window window3(&window_delegate3);
   window3.set_id(3);
   window3.Init(ui::Layer::LAYER_TEXTURED);
   window3.SetBounds(gfx::Rect(10, 10, 50, 50));
   window3.Show();
   window3.SetParent(&window2);
 
-  aura::RootWindow::GetInstance()->ShowRootWindow();
+  root_window->ShowRootWindow();
   MessageLoopForUI::current()->Run();
 
   ui::CompositorTestSupport::Terminate();
 
   return 0;
 }