Move Singleton and related structs to namespace base

chrome/browser/extensions/blacklist_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 "chrome/browser/extensions/blacklist.h"
 #include "chrome/browser/extensions/blacklist_factory.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "extensions/browser/extension_prefs.h"
 #include "extensions/browser/extension_prefs_factory.h"
 #include "extensions/browser/extensions_browser_client.h"
 
 using content::BrowserContext;
 
 namespace extensions {
 
 // static
 Blacklist* BlacklistFactory::GetForBrowserContext(BrowserContext* context) {
   return static_cast<Blacklist*>(
       GetInstance()->GetServiceForBrowserContext(context, true));
 }
 
 // static
 BlacklistFactory* BlacklistFactory::GetInstance() {
-  return Singleton<BlacklistFactory>::get();
+  return base::Singleton<BlacklistFactory>::get();
 }
 
 BlacklistFactory::BlacklistFactory()
     : BrowserContextKeyedServiceFactory(
           "Blacklist",
           BrowserContextDependencyManager::GetInstance()) {
   DependsOn(extensions::ExtensionPrefsFactory::GetInstance());
 }
 
 BlacklistFactory::~BlacklistFactory() {
 }
 
 KeyedService* BlacklistFactory::BuildServiceInstanceFor(
     BrowserContext* context) const {
   return new Blacklist(ExtensionPrefs::Get(context));
 }
 
 BrowserContext* BlacklistFactory::GetBrowserContextToUse(
     BrowserContext* context) const {
   // Redirected in incognito.
   return ExtensionsBrowserClient::Get()->GetOriginalContext(context);
 }
 
 }  // namespace extensions