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

chrome/browser/browser_keyevents_browsertest.cc

Index: chrome/browser/browser_keyevents_browsertest.cc
diff --git a/chrome/browser/browser_keyevents_browsertest.cc b/chrome/browser/browser_keyevents_browsertest.cc
index 49b1ce90f095390c3d0999d7c4b2cc77aa655b62..8c95ada3850fda17a7fb978173f675004c718756 100644
--- a/chrome/browser/browser_keyevents_browsertest.cc
+++ b/chrome/browser/browser_keyevents_browsertest.cc
@@ -109,9 +109,9 @@ class TestFinishObserver : public content::NotificationObserver {
     return finished_;
   }
 
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) override {
+  void Observe(int type,
+               const content::NotificationSource& source,
+               const content::NotificationDetails& details) override {
     DCHECK(type == content::NOTIFICATION_DOM_OPERATION_RESPONSE);
     content::Details<DomOperationNotificationDetails> dom_op_details(details);
     // We might receive responses for other script execution, but we only