Move Singleton and related structs to namespace base

extensions/browser/app_window/app_window_registry.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 "extensions/browser/app_window/app_window_registry.h"
 
 #include <string>
 #include <vector>
 
 #include "base/strings/stringprintf.h"
@@ skipping 221 matching lines @@
 
 // static
 AppWindowRegistry* AppWindowRegistry::Factory::GetForBrowserContext(
     content::BrowserContext* context,
     bool create) {
   return static_cast<AppWindowRegistry*>(
       GetInstance()->GetServiceForBrowserContext(context, create));
 }
 
 AppWindowRegistry::Factory* AppWindowRegistry::Factory::GetInstance() {
-  return Singleton<AppWindowRegistry::Factory>::get();
+  return base::Singleton<AppWindowRegistry::Factory>::get();
 }
 
 AppWindowRegistry::Factory::Factory()
     : BrowserContextKeyedServiceFactory(
           "AppWindowRegistry",
           BrowserContextDependencyManager::GetInstance()) {}
 
 AppWindowRegistry::Factory::~Factory() {}
 
 KeyedService* AppWindowRegistry::Factory::BuildServiceInstanceFor(
     content::BrowserContext* context) const {
   return new AppWindowRegistry(context);
 }
 
 bool AppWindowRegistry::Factory::ServiceIsCreatedWithBrowserContext() const {
   return true;
 }
 
 bool AppWindowRegistry::Factory::ServiceIsNULLWhileTesting() const {
   return false;
 }
 
 content::BrowserContext* AppWindowRegistry::Factory::GetBrowserContextToUse(
     content::BrowserContext* context) const {
   return ExtensionsBrowserClient::Get()->GetOriginalContext(context);
 }
 
 }  // namespace extensions