Move Singleton and related structs to namespace base

chrome/browser/extensions/api/search_engines_private/search_engines_private_event_router_factory.cc

 // Copyright 2015 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/search_engines_private/search_engines_private_event_router.h"
 #include "chrome/browser/extensions/api/search_engines_private/search_engines_private_event_router_factory.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "content/public/browser/browser_context.h"
 #include "extensions/browser/extension_system_provider.h"
 #include "extensions/browser/extensions_browser_client.h"
 
 namespace extensions {
 
 // static
 SearchEnginesPrivateEventRouter*
 SearchEnginesPrivateEventRouterFactory::GetForProfile(
     content::BrowserContext* context) {
   return static_cast<SearchEnginesPrivateEventRouter*>(
       GetInstance()->GetServiceForBrowserContext(context, true));
 }
 
 // static
 SearchEnginesPrivateEventRouterFactory*
 SearchEnginesPrivateEventRouterFactory::GetInstance() {
-  return Singleton<SearchEnginesPrivateEventRouterFactory>::get();
+  return base::Singleton<SearchEnginesPrivateEventRouterFactory>::get();
 }
 
 SearchEnginesPrivateEventRouterFactory::SearchEnginesPrivateEventRouterFactory()
     : BrowserContextKeyedServiceFactory(
           "SearchEnginesPrivateEventRouter",
           BrowserContextDependencyManager::GetInstance()) {
   DependsOn(ExtensionsBrowserClient::Get()->GetExtensionSystemFactory());
 }
 
 SearchEnginesPrivateEventRouterFactory::
@@ skipping 14 matching lines @@
 bool SearchEnginesPrivateEventRouterFactory::
     ServiceIsCreatedWithBrowserContext() const {
   return true;
 }
 
 bool SearchEnginesPrivateEventRouterFactory::ServiceIsNULLWhileTesting() const {
   return false;
 }
 
 }  // namespace extensions