Standardize usage of virtual/override/final in ui/

ui/events/test/test_event_handler.h

Index: ui/events/test/test_event_handler.h
diff --git a/ui/events/test/test_event_handler.h b/ui/events/test/test_event_handler.h
index d50123303ebf60297afcd2e11a05e22084e9aeda..64759c7ef4e79ccf632f3562b3205f9641496dda 100644
--- a/ui/events/test/test_event_handler.h
+++ b/ui/events/test/test_event_handler.h
@@ -22,7 +22,7 @@ namespace test {
 class TestEventHandler : public EventHandler {
  public:
   TestEventHandler();
-  virtual ~TestEventHandler();
+  ~TestEventHandler() override;
 
   int num_key_events() const { return num_key_events_; }
   int num_mouse_events() const { return num_mouse_events_; }
@@ -40,11 +40,11 @@ class TestEventHandler : public EventHandler {
   }
 
   // EventHandler overrides:
-  virtual void OnKeyEvent(KeyEvent* event) override;
-  virtual void OnMouseEvent(MouseEvent* event) override;
-  virtual void OnScrollEvent(ScrollEvent* event) override;
-  virtual void OnTouchEvent(TouchEvent* event) override;
-  virtual void OnGestureEvent(GestureEvent* event) override;
+  void OnKeyEvent(KeyEvent* event) override;
+  void OnMouseEvent(MouseEvent* event) override;
+  void OnScrollEvent(ScrollEvent* event) override;
+  void OnTouchEvent(TouchEvent* event) override;
+  void OnGestureEvent(GestureEvent* event) override;
 
  private:
   // How many events have been received of each type?