Move Singleton and related structs to namespace base

chrome/browser/enhanced_bookmarks/enhanced_bookmark_model_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/enhanced_bookmarks/enhanced_bookmark_model_factory.h"
 
 #include "base/memory/singleton.h"
 #include "chrome/browser/bookmarks/bookmark_model_factory.h"
 #include "chrome/browser/profiles/incognito_helpers.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/enhanced_bookmarks/enhanced_bookmark_model.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "components/version_info/version_info.h"
 
 namespace {
 const char kVersionPrefix[] = "chrome.";
 }
 
 namespace enhanced_bookmarks {
 
 EnhancedBookmarkModelFactory::EnhancedBookmarkModelFactory()
     : BrowserContextKeyedServiceFactory(
           "EnhancedBookmarkModel",
           BrowserContextDependencyManager::GetInstance()) {
   DependsOn(BookmarkModelFactory::GetInstance());
 }
 
 // static
 EnhancedBookmarkModelFactory* EnhancedBookmarkModelFactory::GetInstance() {
-  return Singleton<EnhancedBookmarkModelFactory>::get();
+  return base::Singleton<EnhancedBookmarkModelFactory>::get();
 }
 
 // static
 EnhancedBookmarkModel* EnhancedBookmarkModelFactory::GetForBrowserContext(
     content::BrowserContext* context) {
   DCHECK(!context->IsOffTheRecord());
   return static_cast<EnhancedBookmarkModel*>(
       GetInstance()->GetServiceForBrowserContext(context, true));
 }
 
 KeyedService* EnhancedBookmarkModelFactory::BuildServiceInstanceFor(
     content::BrowserContext* browser_context) const {
   DCHECK(!browser_context->IsOffTheRecord());
   Profile* profile = Profile::FromBrowserContext(browser_context);
 
   return new EnhancedBookmarkModel(
       BookmarkModelFactory::GetForProfile(profile),
       kVersionPrefix + version_info::GetVersionNumber());
 }
 
 content::BrowserContext* EnhancedBookmarkModelFactory::GetBrowserContextToUse(
     content::BrowserContext* context) const {
   return chrome::GetBrowserContextRedirectedInIncognito(context);
 }
 
 }  // namespace enhanced_bookmarks