Get rid of {Run,Terminate}MainApplication(), and more ApplicationDelegate conversion.

examples/authentication_demo/google_authentication_demo.cc

Index: examples/authentication_demo/google_authentication_demo.cc
diff --git a/examples/authentication_demo/google_authentication_demo.cc b/examples/authentication_demo/google_authentication_demo.cc
index 8b5bf06210015af68f9ee6a087c8d1a940d2a969..3ddd52d0f74647ccc0979b1bdfb5161f466d3b57 100644
--- a/examples/authentication_demo/google_authentication_demo.cc
+++ b/examples/authentication_demo/google_authentication_demo.cc
@@ -128,5 +128,5 @@ class GoogleAuthApp : public mojo::ApplicationImplBase {
 
 MojoResult MojoMain(MojoHandle application_request) {
   examples::authentication::GoogleAuthApp google_auth_app;
-  return mojo::RunMainApplication(application_request, &google_auth_app);
+  return mojo::RunApplication(application_request, &google_auth_app);
 }