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

content/browser/media/media_canplaytype_browsertest.cc

Index: content/browser/media/media_canplaytype_browsertest.cc
diff --git a/content/browser/media/media_canplaytype_browsertest.cc b/content/browser/media/media_canplaytype_browsertest.cc
index 6e295ec5c8fc0d815fc9cd0fbbf8bddeb4dfb2fd..e454de461ecd2ea48a142ded00c9a772a4aa1014 100644
--- a/content/browser/media/media_canplaytype_browsertest.cc
+++ b/content/browser/media/media_canplaytype_browsertest.cc
@@ -45,9 +45,7 @@ class MediaCanPlayTypeTest : public MediaBrowserTest {
 public:
   MediaCanPlayTypeTest() : url_("about:blank") { }
 
-  virtual void SetUpOnMainThread() override {
-    NavigateToURL(shell(), url_);
-  }
+  void SetUpOnMainThread() override { NavigateToURL(shell(), url_); }
 
   std::string CanPlay(const std::string& type) {
     std::string command("document.createElement('video').canPlayType(");