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

chrome/renderer/prerender/prerender_media_load_deferrer.h

Index: chrome/renderer/prerender/prerender_media_load_deferrer.h
diff --git a/chrome/renderer/prerender/prerender_media_load_deferrer.h b/chrome/renderer/prerender/prerender_media_load_deferrer.h
index da04af341ca63f140f353f663395110ac23fd2db..2c783892e34e26eca9188977c2ed94e3fda3281a 100644
--- a/chrome/renderer/prerender/prerender_media_load_deferrer.h
+++ b/chrome/renderer/prerender/prerender_media_load_deferrer.h
@@ -18,11 +18,11 @@ class PrerenderMediaLoadDeferrer : public content::RenderFrameObserver {
   // swapped in.
   PrerenderMediaLoadDeferrer(content::RenderFrame* render_frame,
                              const base::Closure& closure);
-  virtual ~PrerenderMediaLoadDeferrer();
+  ~PrerenderMediaLoadDeferrer() override;
 
  private:
   // RenderFrameObserver method:
-  virtual bool OnMessageReceived(const IPC::Message& message) override;
+  bool OnMessageReceived(const IPC::Message& message) override;
 
   void OnSetIsPrerendering(bool is_prerendering);