Standardize usage of virtual/override/final specifiers.

ash/system/audio/volume_view.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 ASH_SYSTEM_AUDIO_VOLUME_VIEW_H_
 #define ASH_SYSTEM_AUDIO_VOLUME_VIEW_H_
 
 #include "ash/system/tray/actionable_view.h"
 #include "ui/gfx/font.h"
 #include "ui/views/controls/button/button.h"
@@ skipping 18 matching lines @@
 class VolumeSlider;
 
 class VolumeView : public ActionableView,
                    public views::ButtonListener,
                    public views::SliderListener {
  public:
   VolumeView(SystemTrayItem* owner,
              system::TrayAudioDelegate* audio_delegate,
              bool is_default_view);
 
-  virtual ~VolumeView();
+  ~VolumeView() override;
 
   void Update();
 
   // Sets volume level on slider_, |percent| is ranged from [0.00] to [1.00].
   void SetVolumeLevel(float percent);
 
  private:
   // Updates bar_, device_type_ icon, and more_ buttons.
   void UpdateDeviceTypeAndMore();
   void HandleVolumeUp(float percent);
   void HandleVolumeDown(float percent);
 
   // Overridden from views::View.
-  virtual void Layout() override;
+  void Layout() override;
 
   // Overridden from views::ButtonListener.
-  virtual void ButtonPressed(views::Button* sender,
-                             const ui::Event& event) override;
+  void ButtonPressed(views::Button* sender, const ui::Event& event) override;
 
   // Overridden from views::SliderListener.
-  virtual void SliderValueChanged(views::Slider* sender,
-                                  float value,
-                                  float old_value,
-                                  views::SliderChangeReason reason) override;
+  void SliderValueChanged(views::Slider* sender,
+                          float value,
+                          float old_value,
+                          views::SliderChangeReason reason) override;
 
   // Overriden from ActionableView.
-  virtual bool PerformAction(const ui::Event& event) override;
+  bool PerformAction(const ui::Event& event) override;
 
   SystemTrayItem* owner_;
   system::TrayAudioDelegate* audio_delegate_;
   VolumeButton* icon_;
   VolumeSlider* slider_;
   BarSeparator* bar_;
   views::ImageView* device_type_;
   views::ImageView* more_;
   bool is_default_view_;
 
   DISALLOW_COPY_AND_ASSIGN(VolumeView);
 };
 
 }  // namespace tray
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_AUDIO_VOLUME_VIEW_H_