Move Singleton and related structs to namespace base

chrome/browser/favicon/chrome_fallback_icon_client_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/favicon/chrome_fallback_icon_client_factory.h"
 
 #include "base/memory/singleton.h"
 #include "chrome/browser/favicon/chrome_fallback_icon_client.h"
 #include "chrome/browser/profiles/incognito_helpers.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
@@ skipping 12 matching lines @@
 favicon::FallbackIconClient*
 ChromeFallbackIconClientFactory::GetForBrowserContext(
     content::BrowserContext* context) {
   return static_cast<favicon::FallbackIconClient*>(
       GetInstance()->GetServiceForBrowserContext(context, true));
 }
 
 // static
 ChromeFallbackIconClientFactory*
 ChromeFallbackIconClientFactory::GetInstance() {
-  return Singleton<ChromeFallbackIconClientFactory>::get();
+  return base::Singleton<ChromeFallbackIconClientFactory>::get();
 }
 
 KeyedService* ChromeFallbackIconClientFactory::BuildServiceInstanceFor(
     content::BrowserContext* context) const {
   return new ChromeFallbackIconClient();
 }