Standardize usage of virtual/override/final specifiers.

content/browser/device_monitor_udev.h

 // Copyright 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.
 
 // This class is used to detect device change and notify base::SystemMonitor
 // on Linux.
 
 #ifndef CONTENT_BROWSER_DEVICE_MONITOR_UDEV_H_
 #define CONTENT_BROWSER_DEVICE_MONITOR_UDEV_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 
 extern "C" {
 struct udev_device;
 }
 
 namespace content {
 
 class UdevLinux;
 
 class DeviceMonitorLinux : public base::MessageLoop::DestructionObserver {
  public:
   DeviceMonitorLinux();
-  virtual ~DeviceMonitorLinux();
+  ~DeviceMonitorLinux() override;
 
  private:
   // This object is deleted on the UI thread after the IO thread has been
   // destroyed. Need to know when IO thread is being destroyed so that
   // we can delete udev_.
-  virtual void WillDestroyCurrentMessageLoop() override;
+  void WillDestroyCurrentMessageLoop() override;
 
   void Initialize();
   void OnDevicesChanged(udev_device* device);
 
   scoped_ptr<UdevLinux> udev_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceMonitorLinux);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DEVICE_MONITOR_UDEV_H_