Standardize usage of virtual/override/final in chrome/browser/

chrome/browser/image_holder_unittest.cc

Index: chrome/browser/image_holder_unittest.cc
diff --git a/chrome/browser/image_holder_unittest.cc b/chrome/browser/image_holder_unittest.cc
index beac7a482c4182c605894830aaf12fe63a4c3bfa..948f11e512d9da80b5048c6c9a477672569a5b43 100644
--- a/chrome/browser/image_holder_unittest.cc
+++ b/chrome/browser/image_holder_unittest.cc
@@ -15,9 +15,7 @@ const char kIconUrl2[] = "http://www.google.com/icon2.jpg";
 class TestDelegate : public chrome::ImageHolderDelegate {
  public:
   TestDelegate() : on_fetch_complete_called_(false) {}
-  virtual void OnFetchComplete() override {
-    on_fetch_complete_called_ = true;
-  }
+  void OnFetchComplete() override { on_fetch_complete_called_ = true; }
   bool on_fetch_complete_called_;
 };