<html>
<head>
<script>
// When we create an XHR from onunload, we expect it to be cancelled almost
// immediately afterwards.  When that happens the XHR's onabort handler is
// called.  The XHR created from there is cancelled again, but at a later point
// after this FRAME has already been detached from its parent.
var requests = [];
function startRequest() {
  var x = new XMLHttpRequest();
  x.open("GET", location, true);
  x.onabort = startRequest;
  x.send(null);
  requests.push(x);
}
</script>
</head>
<body onunload="startRequest()"></body>
</html>