OAuth2SampleRootViewControllerTouch.m includes this comment; it applies
when signing in to Google services.
// By default, the controller will fetch the user's email, but not the
// the user's profile. The full profile can be requested from Google's
// by setting this property before sign-in:
// viewController.signIn.shouldFetchGoogleUserProfile = YES;
// The profile will be available after sign-in as
// NSDictionary *profile = viewController.signIn.userProfile;