pulateForm();
  let orphanRoot = document.createElement('div');
  orphanRoot.appendChild(form);
  orphanRoot.addEventListener('formdata', e => {
    didCallHandler = true;
  });
  new FormData(form);
  assert_true(didCallHandler);
}, '"formdata" event bubbles in an orphan tree.');

for (const enctype of ["application/x-www-form-urlencoded", "multipart/form-data", "text/plain"]) {
  test((t) => {
    let form = populateForm('<input name=file type=file><input name=empty type=file>');
    form.enctype = enctyp