Move Singleton and related structs to namespace base

chrome/browser/history/top_sites_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/history/top_sites_factory.h"
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "chrome/browser/history/history_service_factory.h"
@@ skipping 61 matching lines @@
 
 // static
 scoped_refptr<history::TopSites> TopSitesFactory::GetForProfile(
     Profile* profile) {
   return static_cast<history::TopSites*>(
       GetInstance()->GetServiceForBrowserContext(profile, true).get());
 }
 
 // static
 TopSitesFactory* TopSitesFactory::GetInstance() {
-  return Singleton<TopSitesFactory>::get();
+  return base::Singleton<TopSitesFactory>::get();
 }
 
 // static
 scoped_refptr<history::TopSites> TopSitesFactory::BuildTopSites(
     content::BrowserContext* context,
     const std::vector<history::PrepopulatedPage>& prepopulated_page_list) {
   Profile* profile = Profile::FromBrowserContext(context);
   scoped_refptr<history::TopSitesImpl> top_sites(new history::TopSitesImpl(
       profile->GetPrefs(), HistoryServiceFactory::GetForProfile(
                                profile, ServiceAccessType::EXPLICIT_ACCESS),
@@ skipping 22 matching lines @@
 }
 
 void TopSitesFactory::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   history::TopSitesImpl::RegisterPrefs(registry);
 }
 
 bool TopSitesFactory::ServiceIsNULLWhileTesting() const {
   return true;
 }