Standardize usage of virtual/override/final specifiers.

ash/screensaver/screensaver_view_unittest.cc

Index: ash/screensaver/screensaver_view_unittest.cc
diff --git a/ash/screensaver/screensaver_view_unittest.cc b/ash/screensaver/screensaver_view_unittest.cc
index 4fb096c8455e6fde685bff913b9e8a21e6778676..305300b6a90832a179d0c05764620e3e87768cde 100644
--- a/ash/screensaver/screensaver_view_unittest.cc
+++ b/ash/screensaver/screensaver_view_unittest.cc
@@ -21,9 +21,9 @@ class ScreensaverViewTest : public ash::test::AshTestBase {
     webview_test_helper_.reset(new views::WebViewTestHelper());
   }
 
-  virtual ~ScreensaverViewTest() {}
+  ~ScreensaverViewTest() override {}
 
-  virtual void SetUp() override {
+  void SetUp() override {
     AshTestBase::SetUp();
     RunAllPendingInMessageLoop();
   }