Move Singleton and related structs to namespace base

ui/views/accessibility/ax_aura_obj_cache.cc

 // Copyright 2014 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 "ui/views/accessibility/ax_aura_obj_cache.h"
 
 #include "base/memory/singleton.h"
 #include "base/stl_util.h"
 #include "ui/aura/window.h"
 #include "ui/views/accessibility/ax_aura_obj_wrapper.h"
 #include "ui/views/accessibility/ax_view_obj_wrapper.h"
 #include "ui/views/accessibility/ax_widget_obj_wrapper.h"
 #include "ui/views/accessibility/ax_window_obj_wrapper.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
 
 namespace views {
 
 // static
 AXAuraObjCache* AXAuraObjCache::GetInstance() {
-  return Singleton<AXAuraObjCache>::get();
+  return base::Singleton<AXAuraObjCache>::get();
 }
 
 AXAuraObjWrapper* AXAuraObjCache::GetOrCreate(View* view) {
   return CreateInternal<AXViewObjWrapper>(view, view_to_id_map_);
 }
 
 AXAuraObjWrapper* AXAuraObjCache::GetOrCreate(Widget* widget) {
   return CreateInternal<AXWidgetObjWrapper>(widget, widget_to_id_map_);
 }
 
@@ skipping 110 matching lines @@
 void AXAuraObjCache::RemoveInternal(
     AuraView* aura_view, std::map<AuraView*, int32>& aura_view_to_id_map) {
   int32 id = GetID(aura_view);
   if (id == -1)
     return;
   aura_view_to_id_map.erase(aura_view);
   Remove(id);
 }
 
 }  // namespace views