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

chrome/browser/extensions/webstore_startup_installer.h

 // Copyright (c) 2012 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_WEBSTORE_STARTUP_INSTALLER_H_
 #define CHROME_BROWSER_EXTENSIONS_WEBSTORE_STARTUP_INSTALLER_H_
 
 #include "chrome/browser/extensions/webstore_install_with_prompt.h"
 
 namespace extensions {
 
 // Manages inline installs requested to be performed at startup, e.g. via a
 // command line option: downloads and parses metadata from the webstore,
 // optionally shows an install UI, starts the download once the user
 // confirms.
 //
 // Clients will be notified of success or failure via the |callback| argument
 // passed into the constructor.
 class WebstoreStartupInstaller : public WebstoreInstallWithPrompt {
  public:
   WebstoreStartupInstaller(const std::string& webstore_item_id,
                            Profile* profile,
                            bool show_prompt,
                            const Callback& callback);
 
  protected:
   friend class base::RefCountedThreadSafe<WebstoreStartupInstaller>;
   FRIEND_TEST_ALL_PREFIXES(WebstoreStartupInstallerTest, DomainVerification);
 
-  virtual ~WebstoreStartupInstaller();
+  ~WebstoreStartupInstaller() override;
 
   // Implementations of WebstoreStandaloneInstaller Template Method's hooks.
-  virtual scoped_refptr<ExtensionInstallPrompt::Prompt> CreateInstallPrompt()
+  scoped_refptr<ExtensionInstallPrompt::Prompt> CreateInstallPrompt()
       const override;
 
  private:
   bool show_prompt_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(WebstoreStartupInstaller);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_WEBSTORE_STARTUP_INSTALLER_H_