Move Singleton and related structs to namespace base

chrome/browser/extensions/api/system_indicator/system_indicator_manager_factory.cc

 // Copyright (c) 2012 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 "chrome/browser/extensions/api/system_indicator/system_indicator_manager_factory.h"
 
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/api/extension_action/extension_action_api.h"
 #include "chrome/browser/extensions/api/system_indicator/system_indicator_manager.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "extensions/browser/extension_system_provider.h"
 #include "extensions/browser/extensions_browser_client.h"
 
 namespace extensions {
 
 // static
 SystemIndicatorManager* SystemIndicatorManagerFactory::GetForProfile(
     Profile* profile) {
   return static_cast<SystemIndicatorManager*>(
       GetInstance()->GetServiceForBrowserContext(profile, true));
 }
 
 // static
 SystemIndicatorManagerFactory* SystemIndicatorManagerFactory::GetInstance() {
-  return Singleton<SystemIndicatorManagerFactory>::get();
+  return base::Singleton<SystemIndicatorManagerFactory>::get();
 }
 
 SystemIndicatorManagerFactory::SystemIndicatorManagerFactory()
     : BrowserContextKeyedServiceFactory(
         "SystemIndicatorManager",
         BrowserContextDependencyManager::GetInstance()) {
   DependsOn(ExtensionsBrowserClient::Get()->GetExtensionSystemFactory());
   DependsOn(ExtensionActionAPI::GetFactoryInstance());
 }
 
 SystemIndicatorManagerFactory::~SystemIndicatorManagerFactory() {}
 
 KeyedService* SystemIndicatorManagerFactory::BuildServiceInstanceFor(
     content::BrowserContext* profile) const {
   StatusTray* status_tray = g_browser_process->status_tray();
   if (status_tray == NULL)
     return NULL;
 
   return new SystemIndicatorManager(static_cast<Profile*>(profile),
                                     status_tray);
 }
 
 }  // namespace extensions