Move Singleton and related structs to namespace base

apps/app_lifetime_monitor_factory.cc

 // Copyright 2013 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 "apps/app_lifetime_monitor_factory.h"
 
 #include "apps/app_lifetime_monitor.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "extensions/browser/app_window/app_window_registry.h"
 #include "extensions/browser/extensions_browser_client.h"
 
 namespace apps {
 
 // static
 AppLifetimeMonitor* AppLifetimeMonitorFactory::GetForProfile(Profile* profile) {
   return static_cast<AppLifetimeMonitor*>(
       GetInstance()->GetServiceForBrowserContext(profile, false));
 }
 
 AppLifetimeMonitorFactory* AppLifetimeMonitorFactory::GetInstance() {
-  return Singleton<AppLifetimeMonitorFactory>::get();
+  return base::Singleton<AppLifetimeMonitorFactory>::get();
 }
 
 AppLifetimeMonitorFactory::AppLifetimeMonitorFactory()
     : BrowserContextKeyedServiceFactory(
         "AppLifetimeMonitor",
         BrowserContextDependencyManager::GetInstance()) {
   DependsOn(extensions::AppWindowRegistry::Factory::GetInstance());
 }
 
 AppLifetimeMonitorFactory::~AppLifetimeMonitorFactory() {}
 
 KeyedService* AppLifetimeMonitorFactory::BuildServiceInstanceFor(
     content::BrowserContext* profile) const {
   return new AppLifetimeMonitor(static_cast<Profile*>(profile));
 }
 
 bool AppLifetimeMonitorFactory::ServiceIsCreatedWithBrowserContext() const {
   return true;
 }
 
 content::BrowserContext* AppLifetimeMonitorFactory::GetBrowserContextToUse(
     content::BrowserContext* context) const {
   return extensions::ExtensionsBrowserClient::Get()->
       GetOriginalContext(context);
 }
 
 }  // namespace apps