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

ui/app_list/page_switcher.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_PAGE_SWITCHER_H_
-#define UI_APP_LIST_PAGE_SWITCHER_H_
-
-#include "base/basictypes.h"
-#include "ui/app_list/pagination_model_observer.h"
-#include "ui/views/controls/button/button.h"
-#include "ui/views/view.h"
-
-namespace app_list {
-
-class PaginationModel;
-
-// PageSwitcher represents its underlying PaginationModel with a button strip.
-// Each page in the PageinationModel has a button in the strip and when the
-// button is clicked, the corresponding page becomes selected.
-class PageSwitcher : public views::View,
-                     public views::ButtonListener,
-                     public PaginationModelObserver {
- public:
-  explicit PageSwitcher(PaginationModel* model);
-  virtual ~PageSwitcher();
-
-  // Returns the page index of the page switcher button under the point. If no
-  // page switcher button is under the point, -1 is return. |point| is in
-  // PageSwitcher's coordinates.
-  int GetPageForPoint(const gfx::Point& point) const;
-
-  // Shows hover for button under the point. |point| is in PageSwitcher's
-  // coordinates.
-  void UpdateUIForDragPoint(const gfx::Point& point);
-
-  // Overridden from views::View:
-  virtual gfx::Size GetPreferredSize() OVERRIDE;
-  virtual void Layout() OVERRIDE;
-
- private:
-  void CalculateButtonWidthAndSpacing(int contents_width);
-
-  // Overridden from views::ButtonListener:
-  virtual void ButtonPressed(views::Button* sender,
-                             const ui::Event& event) OVERRIDE;
-
-  // Overridden from PaginationModelObserver:
-  virtual void TotalPagesChanged() OVERRIDE;
-  virtual void SelectedPageChanged(int old_selected, int new_selected) OVERRIDE;
-  virtual void TransitionChanged() OVERRIDE;
-
-  PaginationModel* model_;  // Owned by parent AppListView.
-  views::View* buttons_;  // Owned by views hierarchy.
-
-  DISALLOW_COPY_AND_ASSIGN(PageSwitcher);
-};
-
-}  // namespace app_list
-
-#endif  // UI_APP_LIST_PAGE_SWITCHER_H_