Update {virtual,override,final} to follow C++11 style.

content/shell/browser/shell.h

Index: content/shell/browser/shell.h
diff --git a/content/shell/browser/shell.h b/content/shell/browser/shell.h
index bb8db4ff4677e28067428b49d4f0542f1dc878cf..3bd2f451186a51ab1b55b7c230e8a9551c706551 100644
--- a/content/shell/browser/shell.h
+++ b/content/shell/browser/shell.h
@@ -121,8 +121,7 @@ class Shell : public WebContentsDelegate,
   void LoadingStateChanged(WebContents* source,
                            bool to_different_document) override;
 #if defined(OS_ANDROID)
-  virtual void LoadProgressChanged(WebContents* source,
-                                   double progress) override;
+  void LoadProgressChanged(WebContents* source, double progress) override;
 #endif
   void EnterFullscreenModeForTab(WebContents* web_contents,
                                  const GURL& origin) override;