code: function onSignInWithGenericIdPCredential() {
    var providerId = $('#signin-generic-idp-provider-id').val();
    var idToken = $('#signin-generic-idp-id-token').val();
    var accessToken = $('#signin-generic-idp-access-token').val();
    var provider = new firebase.auth.OAuthProvider(providerId);
    auth.signInWithCredential(
        provider.credential(idToken, accessToken))
        .then(onAuthUserCredentialSuccess, onAuthError);
  }
docs: Signs in with a generic IdP credential.