Adds code for a new Aura shell.

ui/aura_shell/desktop_layout_manager.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_DESKTOP_LAYOUT_MANAGER_H_
+#define UI_AURA_SHELL_DESKTOP_LAYOUT_MANAGER_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "ui/aura/layout_manager.h"
+
+namespace aura {
+class Window;
+}
+namespace views {
+class Widget;
+}
+
+class DesktopLayoutManager : public aura::LayoutManager {
+ public:
+  explicit DesktopLayoutManager(aura::Window* owner);
+  virtual ~DesktopLayoutManager();
+
+  void set_background_widget(views::Widget* background_widget) {
+    background_widget_ = background_widget;
+  }
+
+ private:
+  // Overridden from aura::LayoutManager:
+  virtual void OnWindowResized() OVERRIDE;
+
+  aura::Window* owner_;
+  views::Widget* background_widget_;
+
+  DISALLOW_COPY_AND_ASSIGN(DesktopLayoutManager);
+};
+
+#endif  // UI_AURA_SHELL_DESKTOP_LAYOUT_MANAGER_H_