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

chrome/browser/extensions/signin/gaia_auth_extension_loader.h

 // Copyright 2013 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_EXTENSIONS_SIGNIN_GAIA_AUTH_EXTENSION_LOADER_H_
 #define CHROME_BROWSER_EXTENSIONS_SIGNIN_GAIA_AUTH_EXTENSION_LOADER_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "extensions/browser/browser_context_keyed_api_factory.h"
 
 namespace content {
 class BrowserContext;
 }
 
 namespace extensions {
 
 const char kGaiaAuthExtensionId[] = "mfffpogegjflfpflabcdkioaeobkgjik";
 const char kGaiaAuthExtensionOrigin[] =
       "chrome-extension://mfffpogegjflfpflabcdkioaeobkgjik";
 
 // Manages and registers the gaia auth extension with the extension system.
 class GaiaAuthExtensionLoader : public BrowserContextKeyedAPI {
  public:
   explicit GaiaAuthExtensionLoader(content::BrowserContext* context);
-  virtual ~GaiaAuthExtensionLoader();
+  ~GaiaAuthExtensionLoader() override;
 
   // Load the gaia auth extension if the extension is not loaded yet.
   void LoadIfNeeded();
   // Unload the gaia auth extension if no pending reference.
   void UnloadIfNeeded();
 
   static GaiaAuthExtensionLoader* Get(content::BrowserContext* context);
 
   // BrowserContextKeyedAPI implementation.
   static BrowserContextKeyedAPIFactory<GaiaAuthExtensionLoader>*
       GetFactoryInstance();
 
  private:
   friend class BrowserContextKeyedAPIFactory<GaiaAuthExtensionLoader>;
 
   // KeyedService overrides:
-  virtual void Shutdown() override;
+  void Shutdown() override;
 
   // BrowserContextKeyedAPI implementation.
   static const char* service_name() {
     return "GaiaAuthExtensionLoader";
   }
   static const bool kServiceRedirectedInIncognito = true;
 
   content::BrowserContext* browser_context_;
   int load_count_;
 
   DISALLOW_COPY_AND_ASSIGN(GaiaAuthExtensionLoader);
 };
 
 } // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_SIGNIN_GAIA_AUTH_EXTENSION_LOADER_H_