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

chrome/browser/extensions/external_policy_loader.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_EXTERNAL_POLICY_LOADER_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTERNAL_POLICY_LOADER_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 16 matching lines @@
   enum InstallationType {
     // Installed extensions are not allowed to be disabled or removed.
     FORCED,
     // Installed extensions are allowed to be disabled but not removed.
     RECOMMENDED
   };
 
   ExternalPolicyLoader(ExtensionManagement* settings, InstallationType type);
 
   // ExtensionManagement::Observer implementation
-  virtual void OnExtensionManagementSettingsChanged() override;
+  void OnExtensionManagementSettingsChanged() override;
 
   // Adds an extension to be updated to the pref dictionary.
   static void AddExtension(base::DictionaryValue* dict,
                            const std::string& extension_id,
                            const std::string& update_url);
 
  protected:
-  virtual void StartLoading() override;
+  void StartLoading() override;
 
  private:
   friend class base::RefCountedThreadSafe<ExternalLoader>;
 
-  virtual ~ExternalPolicyLoader();
+  ~ExternalPolicyLoader() override;
 
   ExtensionManagement* settings_;
   InstallationType type_;
 
   DISALLOW_COPY_AND_ASSIGN(ExternalPolicyLoader);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTERNAL_POLICY_LOADER_H_