Standardize usage of virtual/override/final in apps/

apps/app_load_service_factory.h

Index: apps/app_load_service_factory.h
diff --git a/apps/app_load_service_factory.h b/apps/app_load_service_factory.h
index fec014cc6ec7d4132fa62a1ee12b1c143bde67c0..68fa7db82b36ae1fbf20e4dde1727047f01fc244 100644
--- a/apps/app_load_service_factory.h
+++ b/apps/app_load_service_factory.h
@@ -24,14 +24,14 @@ class AppLoadServiceFactory : public BrowserContextKeyedServiceFactory {
   friend struct DefaultSingletonTraits<AppLoadServiceFactory>;
 
   AppLoadServiceFactory();
-  virtual ~AppLoadServiceFactory();
+  ~AppLoadServiceFactory() override;
 
   // BrowserContextKeyedServiceFactory:
-  virtual KeyedService* BuildServiceInstanceFor(
+  KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const override;
-  virtual bool ServiceIsCreatedWithBrowserContext() const override;
-  virtual bool ServiceIsNULLWhileTesting() const override;
-  virtual content::BrowserContext* GetBrowserContextToUse(
+  bool ServiceIsCreatedWithBrowserContext() const override;
+  bool ServiceIsNULLWhileTesting() const override;
+  content::BrowserContext* GetBrowserContextToUse(
       content::BrowserContext* context) const override;
 };