third_party/WebKit/PerformanceTests/DOM/TraverseChildNodes.html

<!DOCTYPE html>
<html>
<body>
<script src="../resources/runner.js"></script>
<script>
var spec = PerfTestRunner.loadFile("../Parser/resources/html5.html");
var iframe;

PerfTestRunner.measureTime({
    description: "Measures performance of traversing through a large HTML document using elem.childNodes.",
    setup: function () {
        if (iframe)
            document.body.removeChild(iframe);
        iframe = document.createElement("iframe");
        iframe.style.display = "none";  // Prevent creation of the rendering tree, so we only test HTML parsing.
        iframe.sandbox = '';  // Prevent external script loads which could cause write() to return before completing the parse.
        document.body.appendChild(iframe);
        iframe.contentDocument.open();
        iframe.contentDocument.write(spec);
        iframe.contentDocument.close();
    },
    run: function() {
        var elements = iframe.contentDocument.getElementsByTagName('*');
        for (var i = 0; i < elements.length; i++) {
            for (var j = 0; j < elements[i].childNodes.length; j++)
                elements[i].childNodes[j];
        }
    },
    done: function () { document.body.removeChild(iframe); }});

</script>
</body>
</html>