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

chrome/browser/ui/screen_capture_notification_ui_stub.cc

Index: chrome/browser/ui/screen_capture_notification_ui_stub.cc
diff --git a/chrome/browser/ui/screen_capture_notification_ui_stub.cc b/chrome/browser/ui/screen_capture_notification_ui_stub.cc
index 18dafa2da7ec1b4aa3f27f7b4e3d15fc5df0adec..0eab3ee91d2fd4cc6dda8f44f6ef37070da5d733 100644
--- a/chrome/browser/ui/screen_capture_notification_ui_stub.cc
+++ b/chrome/browser/ui/screen_capture_notification_ui_stub.cc
@@ -10,10 +10,9 @@
 class ScreenCaptureNotificationUIStub : public ScreenCaptureNotificationUI {
  public:
   ScreenCaptureNotificationUIStub() {}
-  virtual ~ScreenCaptureNotificationUIStub() {}
+  ~ScreenCaptureNotificationUIStub() override {}
 
-  virtual gfx::NativeViewId OnStarted(const base::Closure& stop_callback)
-      override {
+  gfx::NativeViewId OnStarted(const base::Closure& stop_callback) override {
     NOTIMPLEMENTED();
     return 0;
   }