Rename the aura_shell namespace to ash

ash/app_list/app_list_item_model.cc

 // 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.
 
 #include "ash/app_list/app_list_item_model.h"
 
 #include "ash/app_list/app_list_item_model_observer.h"
 
-namespace aura_shell {
+namespace ash {
 
 AppListItemModel::AppListItemModel() {
 }
 
 AppListItemModel::~AppListItemModel() {
 }
 
 void AppListItemModel::SetIcon(const SkBitmap& icon) {
   icon_ = icon;
   FOR_EACH_OBSERVER(AppListItemModelObserver, observers_,
                     ItemIconChanged());
 }
 
 void AppListItemModel::SetTitle(const std::string& title) {
   title_ = title;
   FOR_EACH_OBSERVER(AppListItemModelObserver, observers_,
                     ItemTitleChanged());
 }
 
 void AppListItemModel::AddObserver(AppListItemModelObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void AppListItemModel::RemoveObserver(AppListItemModelObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
-}  // namespace aura_shell
+}  // namespace ash