Standardize usage of virtual/override/final in extensions/

extensions/renderer/user_script_set_manager.h

Index: extensions/renderer/user_script_set_manager.h
diff --git a/extensions/renderer/user_script_set_manager.h b/extensions/renderer/user_script_set_manager.h
index fb6bd6173020713b5b431b08ff34fd7abb76d45e..b0aaf8f5a97ea35f55b1ad6899d833cd6305ddbf 100644
--- a/extensions/renderer/user_script_set_manager.h
+++ b/extensions/renderer/user_script_set_manager.h
@@ -51,7 +51,7 @@ class UserScriptSetManager : public content::RenderProcessObserver {
 
   UserScriptSetManager(const ExtensionSet* extensions);
 
-  virtual ~UserScriptSetManager();
+  ~UserScriptSetManager() override;
 
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
@@ -83,7 +83,7 @@ class UserScriptSetManager : public content::RenderProcessObserver {
   typedef std::map<ExtensionId, linked_ptr<UserScriptSet> > UserScriptSetMap;
 
   // content::RenderProcessObserver implementation.
-  virtual bool OnControlMessageReceived(const IPC::Message& message) override;
+  bool OnControlMessageReceived(const IPC::Message& message) override;
 
   UserScriptSet* GetProgrammaticScriptsByExtension(
       const ExtensionId& extensionId);