lots-of-small-unbreakable-blocks-balanced.html

<!DOCTYPE html>
<script src="../../resources/runner.js"></script>
<pre id="log"></pre>
<div id="target" style="display:none; columns:5;">
  <script>
    for (var i = 0; i < 1000; i++)
      document.write("<div>text</div>\n");
  </script>
</div>
<script>
  var style = document.getElementById("target").style;
  function test() {
    style.display = "block";
    PerfTestRunner.forceLayout();
    style.display = "none";
    PerfTestRunner.forceLayout();
  }

  PerfTestRunner.measureRunsPerSecond({
    description: "Multicol layout with lots blocks and column balancing.",
    run: test
  });
</script>

chromium/third_party/blink/perf_tests/layout/multicol/lots-of-small-unbreakable-blocks-balanced.html