Rename the aura_shell namespace to ash

ash/launcher/launcher_model_observer.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_LAUNCHER_LAUNCHER_MODEL_OBSERVER_H_
 #define ASH_LAUNCHER_LAUNCHER_MODEL_OBSERVER_H_
 #pragma once
 
 #include "ash/ash_export.h"
 
-namespace aura_shell {
+namespace ash {
 
 class ASH_EXPORT LauncherModelObserver {
  public:
   // Invoked after an item has been added to the model.
   virtual void LauncherItemAdded(int index) = 0;
 
   // Invoked after an item has been removed. |index| is the index the item was
   // at.
   virtual void LauncherItemRemoved(int index) = 0;
 
   // Invoked after an item has been moved. See LauncherModel::Move() for details
   // of the arguments.
   virtual void LauncherItemMoved(int start_index, int target_index) = 0;
 
   // Invoked when the images of an item change.
   virtual void LauncherItemImagesChanged(int index) = 0;
 
   // Signals that LauncherItemImagesChanged() is going to be sent in the
   // near future.
   virtual void LauncherItemImagesWillChange(int index) = 0;
 
  protected:
   virtual ~LauncherModelObserver() {}
 };
 
-}  // namespace aura_shell
+}  // namespace ash
 
 #endif  // ASH_LAUNCHER_LAUNCHER_MODEL_OBSERVER_H_