Changes around the launcher so that it only shows the most recently

ui/aura_shell/launcher/tabbed_launcher_button.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_LAUNCHER_TABBED_LAUNCHER_BUTTON_H_
 #define UI_AURA_SHELL_LAUNCHER_TABBED_LAUNCHER_BUTTON_H_
 #pragma once
 
 #include "ui/aura_shell/launcher/launcher_types.h"
 #include "views/controls/button/custom_button.h"
@@ skipping 22 matching lines @@
   virtual bool OnMousePressed(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseReleased(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseCaptureLost() OVERRIDE;
   virtual bool OnMouseDragged(const views::MouseEvent& event) OVERRIDE;
 
  private:
   LauncherTabbedImages images_;
 
   LauncherButtonHost* host_;
 
-  static SkBitmap* bg_image_;
+  // Background images. Which one is chosen depends upon how many images are
+  // provided.
+  static SkBitmap* bg_image_1_;
+  static SkBitmap* bg_image_2_;
+  static SkBitmap* bg_image_3_;
 
   DISALLOW_COPY_AND_ASSIGN(TabbedLauncherButton);
 };
 
 }  // namespace internal
 }  // namespace aura_shell
 
 #endif  // UI_AURA_SHELL_LAUNCHER_TABBED_LAUNCHER_BUTTON_H_