Standardize usage of virtual/override/final specifiers.

ui/views/widget/desktop_aura/x11_window_event_filter.h

Index: ui/views/widget/desktop_aura/x11_window_event_filter.h
diff --git a/ui/views/widget/desktop_aura/x11_window_event_filter.h b/ui/views/widget/desktop_aura/x11_window_event_filter.h
index e21097c8a2512b86c788a5cf95e81f9c59e8465b..b8750ec7fb2a09a0876e2676ee6aa0b5606b8a0c 100644
--- a/ui/views/widget/desktop_aura/x11_window_event_filter.h
+++ b/ui/views/widget/desktop_aura/x11_window_event_filter.h
@@ -30,10 +30,10 @@ class NativeWidgetAura;
 class VIEWS_EXPORT X11WindowEventFilter : public ui::EventHandler {
  public:
   explicit X11WindowEventFilter(DesktopWindowTreeHost* window_tree_host);
-  virtual ~X11WindowEventFilter();
+  ~X11WindowEventFilter() override;
 
   // Overridden from ui::EventHandler:
-  virtual void OnMouseEvent(ui::MouseEvent* event) override;
+  void OnMouseEvent(ui::MouseEvent* event) override;
 
  private:
   // Called when the user clicked the caption area.