<html>
<head>
<script>  
if (window.testRunner)
    testRunner.dumpAsText();
            
function test() {
    var start = new Date().getTime();
    var e = document.getElementById('t');
    var console = document.getElementById('console');
    for (n = 0; n < 1000; n++)
        e.offsetLeft;
    var time = new Date().getTime() - start;
    console.innerHTML = ((time < 500) ? "<span style='color:green'>PASS</span> " :  "<span style='color:red'>FAIL</span> ");// + time;

    if (window.testRunner)
        testRunner.notifyDone();
}
</script>

<link rel=stylesheet href="http://127.0.0.1:8000/local/slow-css-pass.cgi">

</head>
<body>
This page has a slow loading external style sheet. Calling offsetLeft shouldn't be slow when stylesheets are loading. 
Works as HTTP test only.
<div id=console></div>
<div id=t></div>
<script>
if (window.testRunner)
    testRunner.waitUntilDone();
// increase document complexity a bit
for (n = 0; n < 500; n++)
    document.write("<div><span></span><div><span></span></div></div>");
setTimeout(test, 0);
</script>
</body>
</html>