subtree-layout-scrollable-area.html

<!DOCTYPE html>
<style>
div {
    width: 200px;
    height: 50px;
    position: absolute;
    left: 0;
    top: 0;
    overflow: hidden;
}
</style>
<script src="../resources/runner.js"></script>
<script>
  let textNodes = [];
  const NUM_ELEMENTS = 5000;

  function populateData() {
      for (let i = 0; i < NUM_ELEMENTS; i++) {
          let div = document.createElement('div');
          let textNode = document.createTextNode('' + (100 * Math.random()).toFixed(2));
          div.appendChild(textNode);
          textNodes.push(textNode);
          document.body.appendChild(div);
      }
  }

  function startTest() {
    populateData();

    PerfTestRunner.forceLayout();

    PerfTestRunner.measureTime({
      description: "Measures performance of changing text nodes content.",
      run: function() {
        for (let i = 0; i < textNodes.length; i++) {
          textNodes[i].data = '' + (100 * Math.random()).toFixed(2);
        }

        PerfTestRunner.forceLayout();
      },
    });
  }
</script>
<body onload="startTest();">
</body>
chromium/third_party/blink/perf_tests/layout/subtree-layout-scrollable-area.html
