Standardize usage of virtual/override/final in extensions/

extensions/browser/updater/safe_manifest_parser.h

Index: extensions/browser/updater/safe_manifest_parser.h
diff --git a/extensions/browser/updater/safe_manifest_parser.h b/extensions/browser/updater/safe_manifest_parser.h
index 2cbc3e61995f0d93da8f216d55f7533f823641ec..3215fa316e8ba68553d56cd5489d0aff02652200 100644
--- a/extensions/browser/updater/safe_manifest_parser.h
+++ b/extensions/browser/updater/safe_manifest_parser.h
@@ -33,13 +33,13 @@ class SafeManifestParser : public content::UtilityProcessHostClient {
   void Start();
 
  private:
-  virtual ~SafeManifestParser();
+  ~SafeManifestParser() override;
 
   // Creates the sandboxed utility process and tells it to start parsing.
   void ParseInSandbox();
 
   // content::UtilityProcessHostClient implementation.
-  virtual bool OnMessageReceived(const IPC::Message& message) override;
+  bool OnMessageReceived(const IPC::Message& message) override;
 
   void OnParseUpdateManifestSucceeded(const UpdateManifest::Results& results);
   void OnParseUpdateManifestFailed(const std::string& error_message);