Move Singleton and related structs to namespace base

chrome/browser/autocomplete/in_memory_url_index_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/autocomplete/in_memory_url_index_factory.h"
 
 #include "base/memory/singleton.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/bookmarks/bookmark_model_factory.h"
 #include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/profiles/incognito_helpers.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/pref_names.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "components/keyed_service/core/service_access_type.h"
 #include "components/omnibox/browser/in_memory_url_index.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/common/url_constants.h"
 
 // static
 InMemoryURLIndex* InMemoryURLIndexFactory::GetForProfile(Profile* profile) {
   return static_cast<InMemoryURLIndex*>(
       GetInstance()->GetServiceForBrowserContext(profile, true));
 }
 
 // static
 InMemoryURLIndexFactory* InMemoryURLIndexFactory::GetInstance() {
-  return Singleton<InMemoryURLIndexFactory>::get();
+  return base::Singleton<InMemoryURLIndexFactory>::get();
 }
 
 InMemoryURLIndexFactory::InMemoryURLIndexFactory()
     : BrowserContextKeyedServiceFactory(
           "InMemoryURLIndex",
           BrowserContextDependencyManager::GetInstance()) {
   DependsOn(BookmarkModelFactory::GetInstance());
   DependsOn(HistoryServiceFactory::GetInstance());
 }
 
@@ skipping 18 matching lines @@
 }
 
 content::BrowserContext* InMemoryURLIndexFactory::GetBrowserContextToUse(
     content::BrowserContext* context) const {
   return chrome::GetBrowserContextRedirectedInIncognito(context);
 }
 
 bool InMemoryURLIndexFactory::ServiceIsNULLWhileTesting() const {
   return true;
 }