Standardize usage of virtual/override/final in extensions/

extensions/common/api/bluetooth/bluetooth_manifest_handler.h

 // Copyright 2014 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 EXTENSIONS_COMMON_API_BLUETOOTH_BLUETOOTH_MANIFEST_HANDLER_H_
 #define EXTENSIONS_COMMON_API_BLUETOOTH_BLUETOOTH_MANIFEST_HANDLER_H_
 
 #include <string>
 #include <vector>
 
 #include "extensions/common/manifest_handler.h"
 
 namespace extensions {
 class Extension;
 class ManifestPermission;
 }
 
 namespace extensions {
 
 // Parses the "bluetooth" manifest key.
 class BluetoothManifestHandler : public ManifestHandler {
  public:
   BluetoothManifestHandler();
-  virtual ~BluetoothManifestHandler();
+  ~BluetoothManifestHandler() override;
 
   // ManifestHandler overrides.
-  virtual bool Parse(Extension* extension, base::string16* error) override;
-  virtual ManifestPermission* CreatePermission() override;
-  virtual ManifestPermission* CreateInitialRequiredPermission(
+  bool Parse(Extension* extension, base::string16* error) override;
+  ManifestPermission* CreatePermission() override;
+  ManifestPermission* CreateInitialRequiredPermission(
       const Extension* extension) override;
 
  private:
   // ManifestHandler overrides.
-  virtual const std::vector<std::string> Keys() const override;
+  const std::vector<std::string> Keys() const override;
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothManifestHandler);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_API_BLUETOOTH_BLUETOOTH_MANIFEST_HANDLER_H_