Move Singleton and related structs to namespace base

chrome/browser/signin/signin_error_notifier_factory_ash.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/signin/signin_error_notifier_factory_ash.h"
 
 #include "ash/shell.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/signin/signin_error_controller_factory.h"
@@ skipping 12 matching lines @@
 
 // static
 SigninErrorNotifier* SigninErrorNotifierFactory::GetForProfile(
     Profile* profile) {
   return static_cast<SigninErrorNotifier*>(
       GetInstance()->GetServiceForBrowserContext(profile, true));
 }
 
 // static
 SigninErrorNotifierFactory* SigninErrorNotifierFactory::GetInstance() {
-  return Singleton<SigninErrorNotifierFactory>::get();
+  return base::Singleton<SigninErrorNotifierFactory>::get();
 }
 
 KeyedService* SigninErrorNotifierFactory::BuildServiceInstanceFor(
     content::BrowserContext* context) const {
   if (!ash::Shell::HasInstance())
     return NULL;
 
   Profile* profile = static_cast<Profile*>(context);
 
   return new SigninErrorNotifier(
       SigninErrorControllerFactory::GetForProfile(profile), profile);
 }