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

chrome/browser/extensions/chrome_notification_observer.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_CHROME_NOTIFICATION_OBSERVER_H_
 #define CHROME_BROWSER_EXTENSIONS_CHROME_NOTIFICATION_OBSERVER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
 class Browser;
 
 namespace content {
 class RenderProcessHost;
 }
 
 namespace extensions {
 
 // Observer for Chrome-specific notifications that need to be relayed to the
 // extensions module.
 class ChromeNotificationObserver : public content::NotificationObserver {
  public:
   ChromeNotificationObserver();
-  virtual ~ChromeNotificationObserver();
+  ~ChromeNotificationObserver() override;
 
   // Notification handlers:
   void OnRendererProcessCreated(content::RenderProcessHost* process);
 
   // content::NotificationObserver overrides:
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) override;
+  void Observe(int type,
+               const content::NotificationSource& source,
+               const content::NotificationDetails& details) override;
 
  private:
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeNotificationObserver);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_CHROME_NOTIFICATION_OBSERVER_H_