<html>
<head>
<script>
if (window.testRunner) {
    window.testRunner.dumpAsText();
    window.testRunner.addUserStyleSheet("#mixedCase { display: none }", true);
}
</script>
</head>
<body>
<script>
document.prepend(document.implementation.createDocumentType("html", 0, 0));
</script>
<div>If the word fail appears below, then test has failed.</div>
<div id="mixedCase">FAIL</div>
</body>
</html>