Standardize usage of virtual/override/final specifiers.

chrome/browser/signin/signin_tracker_unittest.cc

Index: chrome/browser/signin/signin_tracker_unittest.cc
diff --git a/chrome/browser/signin/signin_tracker_unittest.cc b/chrome/browser/signin/signin_tracker_unittest.cc
index d72c3fa49bd11a18d268b36a94b42bbb39bd1b00..e982549ab226a720d435c09c6c97c433bbfb8bb6 100644
--- a/chrome/browser/signin/signin_tracker_unittest.cc
+++ b/chrome/browser/signin/signin_tracker_unittest.cc
@@ -51,7 +51,7 @@ class MockObserver : public SigninTracker::Observer {
 class SigninTrackerTest : public testing::Test {
  public:
   SigninTrackerTest() {}
-  virtual void SetUp() override {
+  void SetUp() override {
     TestingProfile::Builder builder;
     builder.AddTestingFactory(ProfileOAuth2TokenServiceFactory::GetInstance(),
                               BuildFakeProfileOAuth2TokenService);
@@ -69,7 +69,7 @@ class SigninTrackerTest : public testing::Test {
     tracker_ =
         SigninTrackerFactory::CreateForProfile(profile_.get(), &observer_);
   }
-  virtual void TearDown() override {
+  void TearDown() override {
     tracker_.reset();
     profile_.reset();
   }