chromium/third_party/blink/web_tests/fast/loader/resources/frame-creation-removal-iframe.html

<html>
<head>
<script>
function loaded()
{
    var theFrame = parent.document.getElementById('lbIframe');
    if (theFrame)
        parent.document.body.removeChild(theFrame);

    var objIframe = parent.document.createElement("iframe");
    objIframe.setAttribute('id','lbIframe');
    parent.document.body.appendChild(objIframe);
}

</script>
</head>
<body onload="loaded();">
</body>
</html>