Standardize usage of virtual/override/final in content/browser/

content/browser/notification_service_impl_unittest.cc

Index: content/browser/notification_service_impl_unittest.cc
diff --git a/content/browser/notification_service_impl_unittest.cc b/content/browser/notification_service_impl_unittest.cc
index 7bfedc5ba9d95a43394a9805d876b1c16046ce64..1e71e64251d67c00633f5f3facced4b7290c57a1 100644
--- a/content/browser/notification_service_impl_unittest.cc
+++ b/content/browser/notification_service_impl_unittest.cc
@@ -22,9 +22,9 @@ class TestObserver : public NotificationObserver {
 
   int notification_count() const { return notification_count_; }
 
-  virtual void Observe(int type,
-                       const NotificationSource& source,
-                       const NotificationDetails& details) override {
+  void Observe(int type,
+               const NotificationSource& source,
+               const NotificationDetails& details) override {
     ++notification_count_;
   }