Standardize usage of virtual/override/final in mojo/

mojo/application_manager/background_shell_application_loader_unittest.cc

Index: mojo/application_manager/background_shell_application_loader_unittest.cc
diff --git a/mojo/application_manager/background_shell_application_loader_unittest.cc b/mojo/application_manager/background_shell_application_loader_unittest.cc
index acf1a014638c3b92cdaac79b61aa1fd7cff29394..ae9eae9ef0bf4a52e1f151766f0c943dd9be8132 100644
--- a/mojo/application_manager/background_shell_application_loader_unittest.cc
+++ b/mojo/application_manager/background_shell_application_loader_unittest.cc
@@ -13,18 +13,18 @@ namespace {
 class DummyLoader : public ApplicationLoader {
  public:
   DummyLoader() : simulate_app_quit_(true) {}
-  virtual ~DummyLoader() {}
+  ~DummyLoader() override {}
 
   // ApplicationLoader overrides:
-  virtual void Load(ApplicationManager* manager,
-                    const GURL& url,
-                    scoped_refptr<LoadCallbacks> callbacks) override {
+  void Load(ApplicationManager* manager,
+            const GURL& url,
+            scoped_refptr<LoadCallbacks> callbacks) override {
     if (simulate_app_quit_)
       base::MessageLoop::current()->Quit();
   }
 
-  virtual void OnApplicationError(ApplicationManager* manager,
-                                  const GURL& url) override {}
+  void OnApplicationError(ApplicationManager* manager,
+                          const GURL& url) override {}
 
   void DontSimulateAppQuit() { simulate_app_quit_ = false; }