chromium/third_party/blink/web_tests/fast/frames/resources/frameElement-contents.html

<html>
<head>
<script>
function testFrameElement()
{
    var message = document.getElementById("message");
    var element = window.frameElement;
    var elementID = element.getAttribute("id");
    message.appendChild(document.createTextNode("frameElement ID is \"" + elementID + "\"")); 
}
</script>
</head>
<body onload="testFrameElement()">
<div id="message"></div>
</body>
</html>