showInvalidEmail = function(error) {
    firebaseui.auth.ui.element.setValid(component.getEmailElement(), false);
    firebaseui.auth.ui.element.show(component.getEmailErrorElement(),
        firebaseui.auth.widget.handler.common.getErrorMessage(error));
  }
@param {firebaseui.auth.AuthUI} app The current FirebaseUI instance whose
    configuration is used.
@param {firebaseui.auth.ui.page.PasswordLinking|
    firebaseui.auth.ui.page.PasswordSignIn}
    component The UI component.
@package