Standardize usage of virtual/override/final in chrome/browser/signin/

chrome/browser/signin/account_tracker_service_factory.h

 // 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.
 
 #ifndef CHROME_BROWSER_SIGNIN_ACCOUNT_TRACKER_SERVICE_FACTORY_H_
 #define CHROME_BROWSER_SIGNIN_ACCOUNT_TRACKER_SERVICE_FACTORY_H_
 
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 
@@ skipping 12 matching lines @@
   // incognito).
   static AccountTrackerService* GetForProfile(Profile* profile);
 
   // Returns an instance of the AccountTrackerServiceFactory singleton.
   static AccountTrackerServiceFactory* GetInstance();
 
  private:
   friend struct DefaultSingletonTraits<AccountTrackerServiceFactory>;
 
   AccountTrackerServiceFactory();
-  virtual ~AccountTrackerServiceFactory();
+  ~AccountTrackerServiceFactory() override;
 
   // BrowserContextKeyedServiceFactory implementation.
-  virtual void RegisterProfilePrefs(
+  void RegisterProfilePrefs(
       user_prefs::PrefRegistrySyncable* registry) override;
-  virtual KeyedService* BuildServiceInstanceFor(
+  KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const override;
 
   DISALLOW_COPY_AND_ASSIGN(AccountTrackerServiceFactory);
 };
 
 #endif  // CHROME_BROWSER_SIGNIN_ACCOUNT_TRACKER_SERVICE_FACTORY_H_