Move Singleton and related structs to namespace base

extensions/shell/browser/api/vpn_provider/vpn_service_factory.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/api/vpn_provider/vpn_service_factory.h"
 
 #include "base/memory/singleton.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/network/network_handler.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "extensions/browser/api/vpn_provider/vpn_service.h"
 #include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_registry.h"
 
 namespace chromeos {
 
 // This file is a dummy stub for use in appshell.
 
 // static
 VpnService* VpnServiceFactory::GetForBrowserContext(
     content::BrowserContext* context) {
   return static_cast<VpnService*>(
       GetInstance()->GetServiceForBrowserContext(context, true));
 }
 
 // static
 VpnServiceFactory* VpnServiceFactory::GetInstance() {
-  return Singleton<VpnServiceFactory>::get();
+  return base::Singleton<VpnServiceFactory>::get();
 }
 
 VpnServiceFactory::VpnServiceFactory()
     : BrowserContextKeyedServiceFactory(
           "VpnService",
           BrowserContextDependencyManager::GetInstance()) {
 }
 
 VpnServiceFactory::~VpnServiceFactory() {
 }
@@ skipping 11 matching lines @@
   return new VpnService(
       context, "testuser", extensions::ExtensionRegistry::Get(context),
       extensions::EventRouter::Get(context),
       DBusThreadManager::Get()->GetShillThirdPartyVpnDriverClient(),
       NetworkHandler::Get()->network_configuration_handler(),
       NetworkHandler::Get()->network_profile_handler(),
       NetworkHandler::Get()->network_state_handler());
 }
 
 }  // namespace chromeos