code: function(firebaseCredential) {
      var status = false;
      var p = component.executePromiseRequest(
          /** @type {function (): !goog.Promise} */ (
              goog.bind(app.startSignInWithCredential, app)),
          [firebaseCredential],
          function(result) {
            var container = component.getContainer();
            component.dispose();
            firebaseui.auth.widget.handler.handle(
                firebaseui.auth.widget.HandlerName.CALLBACK,
                app,
                container,
                goog.Promise.resolve(result));
            status = true;
          },
          function(error) {
            if (error['name'] && error['name'] == 'cancel') {
              return;
            } else if (error &&
                       error['code'] == 'auth/credential-already-in-use') {
              // Do nothing when anonymous user is getting updated.
              // Developer should handle this in signInFailure callback.
              return;
            } else if (error &&
                       error['code'] == 'auth/email-already-in-use' &&
                       error['email'] && error['credential']) {
              // Email already in use error should trigger account linking flow.
              // Pass error to callback handler to trigger that flow.
              var container = component.getContainer();
              component.dispose();
              firebaseui.auth.widget.handler.handle(
                  firebaseui.auth.widget.HandlerName.CALLBACK,
                  app,
                  container,
                  goog.Promise.reject(error));
              return;
            }
            var errorMessage =
                firebaseui.auth.widget.handler.common.getErrorMessage(error);
            // Show error message in the info bar.
            component.showInfoBar(errorMessage);
          });
      app.registerPending(p);
      return p.then(function() {
        // Status needs to be returned.
        return status;
      }, function(error) {
        return false;
      });
    }
docs: Sign in with a Firebase Auth credential.
  @param {!firebase.auth.AuthCredential} firebaseCredential The Firebase Auth
  credential.
  @return {!goog.Promise<boolean>}