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

chrome/browser/ui/webui/help/version_updater_win.cc

Index: chrome/browser/ui/webui/help/version_updater_win.cc
diff --git a/chrome/browser/ui/webui/help/version_updater_win.cc b/chrome/browser/ui/webui/help/version_updater_win.cc
index 9825fe02ff594e9ff129e41332640258b8937fea..59b66926aeb2c802f9444f5a5f0366fc84384af2 100644
--- a/chrome/browser/ui/webui/help/version_updater_win.cc
+++ b/chrome/browser/ui/webui/help/version_updater_win.cc
@@ -36,11 +36,11 @@ class VersionUpdaterWin : public VersionUpdater {
 
   // Clients must use VersionUpdater::Create().
   VersionUpdaterWin();
-  virtual ~VersionUpdaterWin();
+  ~VersionUpdaterWin() override;
 
   // VersionUpdater implementation.
-  virtual void CheckForUpdate(const StatusCallback& callback) override;
-  virtual void RelaunchBrowser() const override;
+  void CheckForUpdate(const StatusCallback& callback) override;
+  void RelaunchBrowser() const override;
 
   // chrome::UpdateCheckCallback.
   void OnUpdateCheckResults(GoogleUpdateUpgradeResult result,