Move Singleton and related structs to namespace base

chrome/browser/history/web_history_service_factory.cc

 // Copyright (c) 2012 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/web_history_service_factory.h"
 
 #include "chrome/browser/signin/profile_oauth2_token_service_factory.h"
 #include "chrome/browser/signin/signin_manager_factory.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_service_factory.h"
@@ skipping 11 matching lines @@
       ProfileSyncServiceFactory::GetInstance()->GetForProfile(profile);
   return sync &&
       sync->IsSyncActive() &&
       sync->GetActiveDataTypes().Has(syncer::HISTORY_DELETE_DIRECTIVES);
 }
 
 }  // namespace
 
 // static
 WebHistoryServiceFactory* WebHistoryServiceFactory::GetInstance() {
-  return Singleton<WebHistoryServiceFactory>::get();
+  return base::Singleton<WebHistoryServiceFactory>::get();
 }
 
 // static
 history::WebHistoryService* WebHistoryServiceFactory::GetForProfile(
       Profile* profile) {
   if (!IsHistorySyncEnabled(profile))
     return nullptr;
 
   return static_cast<history::WebHistoryService*>(
       GetInstance()->GetServiceForBrowserContext(profile, true));
@@ skipping 16 matching lines @@
 WebHistoryServiceFactory::WebHistoryServiceFactory()
     : BrowserContextKeyedServiceFactory(
         "WebHistoryServiceFactory",
         BrowserContextDependencyManager::GetInstance()) {
   DependsOn(ProfileOAuth2TokenServiceFactory::GetInstance());
   DependsOn(SigninManagerFactory::GetInstance());
 }
 
 WebHistoryServiceFactory::~WebHistoryServiceFactory() {
 }