Skeleton for app_list on OSX, and refactoring for enable_app_list=1 on OS=="mac".

ui/app_list/app_list_background.h

-// 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.
-
-#ifndef UI_APP_LIST_APP_LIST_BACKGROUND_H_
-#define UI_APP_LIST_APP_LIST_BACKGROUND_H_
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "ui/views/background.h"
-
-namespace views {
-class View;
-}
-
-namespace app_list {
-
-// A class to paint bubble background.
-class AppListBackground : public views::Background {
- public:
-  AppListBackground(int corner_radius,
-                    views::View* search_box_view);
-  virtual ~AppListBackground();
-
- private:
-  // views::Background overrides:
-  virtual void Paint(gfx::Canvas* canvas, views::View* view) const OVERRIDE;
-
-  const int corner_radius_;
-  const views::View* search_box_view_;  // Owned by views hierarchy.
-
-  DISALLOW_COPY_AND_ASSIGN(AppListBackground);
-};
-
-}  // namespace app_list
-
-#endif  // UI_APP_LIST_APP_LIST_BACKGROUND_H_