C++11 override style change for athena

athena/extensions/public/extension_app_model_builder.h

Index: athena/extensions/public/extension_app_model_builder.h
diff --git a/athena/extensions/public/extension_app_model_builder.h b/athena/extensions/public/extension_app_model_builder.h
index abd89728f7e035024124f10ccb05bdf531a8ebde..0fba01f527e8729b108a74359a90a7a5e2b07159 100644
--- a/athena/extensions/public/extension_app_model_builder.h
+++ b/athena/extensions/public/extension_app_model_builder.h
@@ -25,18 +25,18 @@ class ATHENA_EXPORT ExtensionAppModelBuilder
       public extensions::ExtensionRegistryObserver {
  public:
   explicit ExtensionAppModelBuilder(content::BrowserContext* browser_context);
-  virtual ~ExtensionAppModelBuilder();
+  ~ExtensionAppModelBuilder() override;
 
-  virtual void RegisterAppListModel(app_list::AppListModel* model) override;
+  void RegisterAppListModel(app_list::AppListModel* model) override;
 
  private:
   void AddItem(scoped_refptr<const extensions::Extension> extension);
 
   // extensions::ExtensionRegistryObserver:
-  virtual void OnExtensionInstalled(content::BrowserContext* browser_context,
+  void OnExtensionInstalled(content::BrowserContext* browser_context,
                                     const extensions::Extension* extension,
                                     bool is_update) override;
-  virtual void OnExtensionUninstalled(
+  void OnExtensionUninstalled(
       content::BrowserContext* browser_context,
       const extensions::Extension* extension,
       extensions::UninstallReason reason) override;