Standardize usage of virtual/override/final specifiers.

ui/message_center/views/message_view_context_menu_controller.h

Index: ui/message_center/views/message_view_context_menu_controller.h
diff --git a/ui/message_center/views/message_view_context_menu_controller.h b/ui/message_center/views/message_view_context_menu_controller.h
index 7c41259a76255bed41a123bc2f834692d6e1e9e6..ce30ebb5513570ee2214204c43877fe364a5e16e 100644
--- a/ui/message_center/views/message_view_context_menu_controller.h
+++ b/ui/message_center/views/message_view_context_menu_controller.h
@@ -16,13 +16,13 @@ class MessageViewContextMenuController : public views::ContextMenuController {
  public:
   explicit MessageViewContextMenuController(
       MessageCenterController* controller);
-  virtual ~MessageViewContextMenuController();
+  ~MessageViewContextMenuController() override;
 
  private:
   // Overridden from views::ContextMenuController:
-  virtual void ShowContextMenuForView(views::View* source,
-                                      const gfx::Point& point,
-                                      ui::MenuSourceType source_type) override;
+  void ShowContextMenuForView(views::View* source,
+                              const gfx::Point& point,
+                              ui::MenuSourceType source_type) override;
 
   MessageCenterController* controller_;