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

chrome/browser/extensions/user_script_loader_unittest.cc

Index: chrome/browser/extensions/user_script_loader_unittest.cc
diff --git a/chrome/browser/extensions/user_script_loader_unittest.cc b/chrome/browser/extensions/user_script_loader_unittest.cc
index 7a6938ec5ec6535b0aaaaf4ce316420b24c286f1..775f82799d0c7ad412017fead96e7cf369d7286e 100644
--- a/chrome/browser/extensions/user_script_loader_unittest.cc
+++ b/chrome/browser/extensions/user_script_loader_unittest.cc
@@ -63,9 +63,9 @@ class UserScriptLoaderTest : public testing::Test,
     ui_thread_.reset();
   }
 
-  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 == extensions::NOTIFICATION_USER_SCRIPTS_UPDATED);
 
     shared_memory_ = content::Details<base::SharedMemory>(details).ptr();