<!doctype html>
<title>Historical iframe element features should not be supported</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id=log></div>
<script>
function t(property) {
  test(function() {
    assert_false(property in document.createElement('iframe'));
  }, 'iframe.' + property + ' should not be supported');
}

// added in https://github.com/whatwg/html/commit/f6490f17f577fa3478791b29ad8c2b586418001f
// removed in https://github.com/whatwg/html/commit/1490eba4dba5ab476f0981443a86c01acae01311
t('seamless');
</script>