Move Singleton and related structs to namespace base

chrome/browser/bitmap_fetcher/bitmap_fetcher_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 "chrome/browser/bitmap_fetcher/bitmap_fetcher_service_factory.h"
 
 #include "chrome/browser/bitmap_fetcher/bitmap_fetcher_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 
 /// Factory
 BitmapFetcherService* BitmapFetcherServiceFactory::GetForBrowserContext(
     content::BrowserContext* profile) {
   return static_cast<BitmapFetcherService*>(
       GetInstance()->GetServiceForBrowserContext(profile, true));
 }
 
 // static
 BitmapFetcherServiceFactory* BitmapFetcherServiceFactory::GetInstance() {
-  return Singleton<BitmapFetcherServiceFactory>::get();
+  return base::Singleton<BitmapFetcherServiceFactory>::get();
 }
 
 BitmapFetcherServiceFactory::BitmapFetcherServiceFactory()
     : BrowserContextKeyedServiceFactory(
           "BitmapFetcherService",
           BrowserContextDependencyManager::GetInstance()) {
 }
 
 BitmapFetcherServiceFactory::~BitmapFetcherServiceFactory() {
 }
 
 KeyedService* BitmapFetcherServiceFactory::BuildServiceInstanceFor(
     content::BrowserContext* context) const {
   Profile* profile = static_cast<Profile*>(context);
   DCHECK(!profile->IsOffTheRecord());
   return new BitmapFetcherService(profile);
 }