Update {virtual,override} to follow C++11 style in chrome.

chrome/browser/first_run/first_run_browsertest.cc

Index: chrome/browser/first_run/first_run_browsertest.cc
diff --git a/chrome/browser/first_run/first_run_browsertest.cc b/chrome/browser/first_run/first_run_browsertest.cc
index 0c97f4c2b6205b30c654989d4b7c0d24e6a79368..25897c129e90263da4e61ad59cc2a49adcecdea2 100644
--- a/chrome/browser/first_run/first_run_browsertest.cc
+++ b/chrome/browser/first_run/first_run_browsertest.cc
@@ -129,7 +129,7 @@ class FirstRunMasterPrefsBrowserTestT
   FirstRunMasterPrefsBrowserTestT() {}
 
  protected:
-  virtual void SetUp() override {
+  void SetUp() override {
     SetMasterPreferencesForTest(Text);
     FirstRunMasterPrefsBrowserTestBase::SetUp();
   }