Use the correct launcher assets for shelf alignment.

ash/launcher/overflow_button.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 ASH_LAUNCHER_OVERFLOW_BUTTON_H_
 #define ASH_LAUNCHER_OVERFLOW_BUTTON_H_
 
 #include "ash/wm/shelf_types.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "ui/views/controls/button/custom_button.h"
 
 namespace gfx {
 class ImageSkia;
 }
 
 namespace ash {
 namespace internal {
 
 // Launcher overflow chevron button.
 class OverflowButton : public views::CustomButton {
  public:
   explicit OverflowButton(views::ButtonListener* listener);
   virtual ~OverflowButton();
 
-  void SetShelfAlignment(ShelfAlignment alignment);
+  void OnShelfAlignmentChanged();
 
  private:
   void PaintBackground(gfx::Canvas* canvas, int alpha);
 
   // views::View overrides:
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
 
-  ShelfAlignment alignment_;
   const gfx::ImageSkia* image_;
 
   DISALLOW_COPY_AND_ASSIGN(OverflowButton);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_LAUNCHER_OVERFLOW_BUTTON_H_