Standardize usage of virtual/override/final specifiers.

ash/system/bluetooth/tray_bluetooth.h

Index: ash/system/bluetooth/tray_bluetooth.h
diff --git a/ash/system/bluetooth/tray_bluetooth.h b/ash/system/bluetooth/tray_bluetooth.h
index 8193c0125f6bb5ad47afcccd6d0594e099f7f20d..af04acfc8afdff9decd8c29752d4ab4e5b1e46e7 100644
--- a/ash/system/bluetooth/tray_bluetooth.h
+++ b/ash/system/bluetooth/tray_bluetooth.h
@@ -18,21 +18,21 @@ class TrayBluetooth : public SystemTrayItem,
                       public BluetoothObserver {
  public:
   explicit TrayBluetooth(SystemTray* system_tray);
-  virtual ~TrayBluetooth();
+  ~TrayBluetooth() override;
 
  private:
   // Overridden from SystemTrayItem.
-  virtual views::View* CreateTrayView(user::LoginStatus status) override;
-  virtual views::View* CreateDefaultView(user::LoginStatus status) override;
-  virtual views::View* CreateDetailedView(user::LoginStatus status) override;
-  virtual void DestroyTrayView() override;
-  virtual void DestroyDefaultView() override;
-  virtual void DestroyDetailedView() override;
-  virtual void UpdateAfterLoginStatusChange(user::LoginStatus status) override;
+  views::View* CreateTrayView(user::LoginStatus status) override;
+  views::View* CreateDefaultView(user::LoginStatus status) override;
+  views::View* CreateDetailedView(user::LoginStatus status) override;
+  void DestroyTrayView() override;
+  void DestroyDefaultView() override;
+  void DestroyDetailedView() override;
+  void UpdateAfterLoginStatusChange(user::LoginStatus status) override;
 
   // Overridden from BluetoothObserver.
-  virtual void OnBluetoothRefresh() override;
-  virtual void OnBluetoothDiscoveringChanged() override;
+  void OnBluetoothRefresh() override;
+  void OnBluetoothDiscoveringChanged() override;
 
   tray::BluetoothDefaultView* default_;
   tray::BluetoothDetailedView* detailed_;