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

chrome/browser/extensions/favicon_downloader_unittest.cc

Index: chrome/browser/extensions/favicon_downloader_unittest.cc
diff --git a/chrome/browser/extensions/favicon_downloader_unittest.cc b/chrome/browser/extensions/favicon_downloader_unittest.cc
index 396466b45db4585c494591ac0e3208e3af2626a2..8d700cca97b42a658753ff490cbfb808669217d3 100644
--- a/chrome/browser/extensions/favicon_downloader_unittest.cc
+++ b/chrome/browser/extensions/favicon_downloader_unittest.cc
@@ -51,14 +51,11 @@ class TestFaviconDownloader : public FaviconDownloader {
                        base::Unretained(this))),
         id_counter_(0) {
   }
-  virtual ~TestFaviconDownloader() {}
+  ~TestFaviconDownloader() override {}
 
-  virtual int DownloadImage(const GURL& url) override {
-    return id_counter_++;
-  }
+  int DownloadImage(const GURL& url) override { return id_counter_++; }
 
-  virtual std::vector<content::FaviconURL> GetFaviconURLsFromWebContents()
-      override {
+  std::vector<content::FaviconURL> GetFaviconURLsFromWebContents() override {
     return initial_favicon_urls_;
   }