LayoutTests/fast/dom/resources/xmlhttprequest-constructor-in-detached-document-frame.html

<script>
    var xhr = new parent.XMLHttpRequest;
    xhr.open("GET", "xmlhttprequest-constructor-in-detached-document-frame.html");
    xhr.onreadystatechange = function(evt) {
        if (evt.target.readyState == 4) {
            parent.setTimeout("pass()", 0);
            var xhrConstructor = XMLHttpRequest; // The constructor may not be reachable as window object property after detaching the frame.
            parent.document.body.removeChild(parent.document.getElementsByTagName("iframe")[0]);
            try {
                var req = new XMLHttpRequest;
            } catch (ex) {
                var req = new xhrConstructor;
            }
            req.open("GET", "xmlhttprequest-constructor-in-detached-document-frame.html", false);
            req.send(null);
        }
    }
    xhr.send(null);
    xhr = null;
</script>