overflow-auto-in-overflow-auto-scrolled.html

<!DOCTYPE html>
<script src="../resources/text-based-repaint.js"></script>
<script>
onload = () => {
  // Scroll the outerDiv until we reach innerDiv.
  outerDiv.scrollTop = 300;
  runRepaintAndPixelTest();
};

function repaintTest() {
  // Now scroll innerDiv once to the green area.
  innerDiv.scrollTop = 400;
}
</script>
<!-- https://bugs.webkit.org/show_bug.cgi?id=71550 -->
<!-- For the test to pass you should not see any RED or PURPLE, only green -->
<div style="height: 300px; overflow-y: auto;" id="outerDiv">
  <div style="height: 300px; background: purple;"></div>
  <div style="height: 400px; overflow-y: auto;" id="innerDiv">
    <div style="height: 400px; width: 300px; background: red"></div>
    <div style="height: 400px; width: 300px; background: green"></div>
  </div>
</div>

chromium/third_party/blink/web_tests/paint/invalidation/scroll/overflow-auto-in-overflow-auto-scrolled.html