Rename the aura_shell namespace to ash

ash/launcher/view_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/launcher/view_model.h"
 
 #include "base/logging.h"
 #include "ui/views/view.h"
 
-namespace aura_shell {
+namespace ash {
 
 ViewModel::ViewModel() {
 }
 
 ViewModel::~ViewModel() {
   // view are owned by their parent, no need to delete them.
 }
 
 void ViewModel::Add(views::View* view, int index) {
   Entry entry;
@@ skipping 24 matching lines @@
 }
 
 int ViewModel::GetIndexOfView(views::View* view) const {
   for (size_t i = 0; i < entries_.size(); ++i) {
     if (entries_[i].view == view)
       return static_cast<int>(i);
   }
   return -1;
 }
 
-}  // namespace aura_shell
+}  // namespace ash