Standardize usage of virtual/override/final in extensions/

extensions/browser/api/hid/hid_connection_resource.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_BROWSER_API_HID_HID_CONNECTION_RESOURCE_H_
 #define EXTENSIONS_BROWSER_API_HID_HID_CONNECTION_RESOURCE_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 15 matching lines @@
   static const content::BrowserThread::ID kThreadId =
       content::BrowserThread::UI;
 #else
   // TODO(reillyg): Migrate Linux/CrOS and Windows as well.
   static const content::BrowserThread::ID kThreadId =
       content::BrowserThread::FILE;
 #endif
 
   HidConnectionResource(const std::string& owner_extension_id,
                         scoped_refptr<device::HidConnection> connection);
-  virtual ~HidConnectionResource();
+  ~HidConnectionResource() override;
 
   scoped_refptr<device::HidConnection> connection() const {
     return connection_;
   }
 
-  virtual bool IsPersistent() const override;
+  bool IsPersistent() const override;
 
   static const char* service_name() { return "HidConnectionResourceManager"; }
 
  private:
   scoped_refptr<device::HidConnection> connection_;
 
   DISALLOW_COPY_AND_ASSIGN(HidConnectionResource);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_HID_HID_CONNECTION_RESOURCE_H_