Standardize usage of virtual/override/final specifiers.

ash/system/user/tray_user_separator.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.
 
 #ifndef ASH_SYSTEM_USER_TRAY_USER_SEPARATOR_H_
 #define ASH_SYSTEM_USER_TRAY_USER_SEPARATOR_H_
 
 #include "ash/ash_export.h"
 #include "ash/system/tray/system_tray_item.h"
 
 namespace ash {
 
 // This tray item is showing an additional separator line between the logged in
 // users and the rest of the system tray menu. The separator will only be shown
 // when there are at least two users logged in.
 class ASH_EXPORT TrayUserSeparator : public SystemTrayItem {
  public:
   explicit TrayUserSeparator(SystemTray* system_tray);
-  virtual ~TrayUserSeparator() {}
+  ~TrayUserSeparator() override {}
 
   // Returns true if the separator gets shown.
   bool separator_shown() { return separator_shown_; }
 
  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 {}
-  virtual void UpdateAfterShelfAlignmentChange(
-      ShelfAlignment alignment) 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 {}
+  void UpdateAfterShelfAlignmentChange(ShelfAlignment alignment) override {}
 
   // True if the separator gets shown.
   bool separator_shown_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayUserSeparator);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_USER_TRAY_USER_SEPARATOR_H_