chromium/third_party/blink/perf_tests/layout/multicol/tall-content-short-columns.html

<!DOCTYPE html>
<!-- Lock the page scale factor to prevent rescaling when the content width changes. -->
<meta name="viewport" content="initial-scale=1.0 minimum-scale=1.0 maximum-scale=1.0">
<script src="../../resources/runner.js"></script>
<body style="overflow:scroll;"> <!-- don't want auto scrollbars to affect the number of layout passes. -->
    <pre id="log"></pre>
    <div id="target" style="position:absolute; top:0; left:0; display:none; columns:2; column-fill:auto; width:40em; height:100px;">
        <div style="height:800000px;"></div>
    </div>
    <script>
    var target = document.getElementById("target");
    var style = target.style;

    function test() {
        style.display = "block";
        PerfTestRunner.forceLayout();

        // Do some hit-testing.
        document.caretRangeFromPoint(10, 10);

        style.display = "none";
        PerfTestRunner.forceLayout();
    }

    PerfTestRunner.measureRunsPerSecond({
        description: "Measures performance of multicol layout with many columns.",
        run: test
    });
    </script>
</body>