Rename the aura_shell namespace to ash

ash/drag_drop/drag_image_view.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 ASH_DRAG_DROP_DRAG_IMAGE_VIEW_H_
 #define ASH_DRAG_DROP_DRAG_IMAGE_VIEW_H_
 #pragma once
 
 #include "ui/views/controls/image_view.h"
 
 namespace views {
 class Widget;
 }
 
-namespace aura_shell {
+namespace ash {
 namespace internal {
 
 class DragImageView : public views::ImageView {
  public:
   DragImageView();
   virtual ~DragImageView();
 
   // Sets the bounds of the native widget.
   void SetScreenBounds(const gfx::Rect& bounds);
 
   // Sets the position of the native widget.
   void SetScreenPosition(const gfx::Point& position);
 
   // Sets the visibility of the native widget.
   void SetWidgetVisible(bool visible);
 
  private:
   scoped_ptr<views::Widget> widget_;
 
   DISALLOW_COPY_AND_ASSIGN(DragImageView);
 };
 
 }  // namespace internal
-}  // namespace aura_shell
+}  // namespace ash
 
 #endif  // ASH_DRAG_DROP_DRAG_IMAGE_VIEW_H_