scrolling-contents-scroll.html | Explore in Territory

<!doctype HTML>
<script src="../resources/run-after-layout-and-paint.js"></script>
<style>
::-webkit-scrollbar {
    display: none;
}
</style>
<div style="column-count: 2; width: 800px; height: 300px;">
  First column. Green should show on scroll.
  <div id="scroller" style="width: 400px; height: 250px;  overflow-y: auto;">
    <div style="width: 300px; height: 300px; background: red"></div>
    <div style="width: 300px; height: 300px; background: green"></div>
  </div>
  Second column.
</div>
<script>
  if (window.testRunner)
    window.testRunner.waitUntilDone();
  runAfterLayoutAndPaint(() => {
    scroller.scrollBy(0, 300);
    if (window.testRunner)
        window.testRunner.notifyDone();
  });
</script>

chromium/third_party/blink/web_tests/fragmentation/scrolling-contents-scroll.html