Standardize usage of virtual/override/final in ui/

ui/message_center/cocoa/notification_controller_unittest.mm

Index: ui/message_center/cocoa/notification_controller_unittest.mm
diff --git a/ui/message_center/cocoa/notification_controller_unittest.mm b/ui/message_center/cocoa/notification_controller_unittest.mm
index 6ff7091fbd1bbd25420c70ca6b265fb57c3f1428..41573e1528c0199da328a21ce04e5f0ecd13f9a3 100644
--- a/ui/message_center/cocoa/notification_controller_unittest.mm
+++ b/ui/message_center/cocoa/notification_controller_unittest.mm
@@ -29,15 +29,14 @@ class MockMessageCenter : public message_center::FakeMessageCenter {
         remove_count_(0),
         last_clicked_index_(-1) {}
 
-  virtual void RemoveNotification(const std::string& id,
-                                  bool by_user) override {
+  void RemoveNotification(const std::string& id, bool by_user) override {
     last_removed_id_ = id;
     last_removed_by_user_ = by_user;
     ++remove_count_;
   }
 
-  virtual void ClickOnNotificationButton(const std::string& id,
-                                         int button_index) override {
+  void ClickOnNotificationButton(const std::string& id,
+                                 int button_index) override {
     last_clicked_id_ = id;
     last_clicked_index_ = button_index;
   }