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

chrome/browser/extensions/api/spellcheck/spellcheck_api.h

 // Copyright (c) 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_API_SPELLCHECK_SPELLCHECK_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_SPELLCHECK_SPELLCHECK_API_H_
 
 #include "base/scoped_observer.h"
 #include "extensions/browser/browser_context_keyed_api_factory.h"
 #include "extensions/browser/extension_registry_observer.h"
 
 namespace extensions {
 class ExtensionRegistry;
 
 class SpellcheckAPI : public BrowserContextKeyedAPI,
                       public ExtensionRegistryObserver {
  public:
   explicit SpellcheckAPI(content::BrowserContext* context);
-  virtual ~SpellcheckAPI();
+  ~SpellcheckAPI() override;
 
   // BrowserContextKeyedAPI implementation.
   static BrowserContextKeyedAPIFactory<SpellcheckAPI>* GetFactoryInstance();
 
  private:
   friend class BrowserContextKeyedAPIFactory<SpellcheckAPI>;
 
   // ExtensionRegistryObserver implementation.
-  virtual void OnExtensionLoaded(content::BrowserContext* browser_context,
-                                 const Extension* extension) override;
-  virtual void OnExtensionUnloaded(
-      content::BrowserContext* browser_context,
-      const Extension* extension,
-      UnloadedExtensionInfo::Reason reason) override;
+  void OnExtensionLoaded(content::BrowserContext* browser_context,
+                         const Extension* extension) override;
+  void OnExtensionUnloaded(content::BrowserContext* browser_context,
+                           const Extension* extension,
+                           UnloadedExtensionInfo::Reason reason) override;
 
   // BrowserContextKeyedAPI implementation.
   static const char* service_name() {
     return "SpellcheckAPI";
   }
 
   // Listen to extension load, unloaded notifications.
   ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
       extension_registry_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(SpellcheckAPI);
 };
 
 template <>
 void BrowserContextKeyedAPIFactory<SpellcheckAPI>::DeclareFactoryDependencies();
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_SPELLCHECK_SPELLCHECK_API_H_