fixed-pos-with-abs-pos-child-scroll.html

<!doctype html>
<html>

<head>
<script src="../../../resources/run-after-layout-and-paint.js"></script>

<style>
  #fixed {
    position: fixed;
    bottom: 30px;
    right: 0px;
  }
  #abs {
    position: absolute;
    bottom: 0px;
    right: 0px;
    height: 90px;
    width: 360px;
    background: yellow;
  }
</style>

<script>
  if (window.testRunner) {
    testRunner.dumpAsText();
    testRunner.waitUntilDone();
  }

  if (window.internals) {
    internals.settings.setPreferCompositingToLCDTextEnabled(false);
  }

  window.onload = function() {
    if (window.internals)
      internals.startTrackingRepaints(document);

    window.scrollTo(0, 500);

    runAfterLayoutAndPaint(function() {
      window.scrollTo(0, 0);

      runAfterLayoutAndPaint(function() {
        if (window.internals)
          document.getElementById('layers').textContent = 
            internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_INVALIDATIONS);

        if (window.testRunner)
            testRunner.notifyDone();
      });
    });
  }
</script>
</head>

<body style="height: 4000px;">
  <div id="fixed">
    <div id="abs">
      Hi!
    </div>
  </div>
  <pre id="layers"></pre>
</body>

</html>

chromium/third_party/blink/web_tests/paint/invalidation/compositing/fixed-pos-with-abs-pos-child-scroll.html