css/css-overflow/incremental-scroll.html

<!DOCTYPE html>
<html class="reftest-wait">
<link rel="help" href="https://drafts.csswg.org/css-overflow-3/#scroll-container">
<link rel="match" href="incremental-scroll-ref.html">
<script src="/common/reftest-wait.js"></script>
<script src="/common/rendering-utils.js"></script>
<div id="target" style="background: white; overflow: scroll; width: 500px; height: 500px;
                        font-size: 40px; will-change: transform">
</div>
<script>
for (var i = 0; i < 500; i++) {
  var div = document.createElement("div");
  div.textContent = i;
  target.appendChild(div);
}

function scroll() {
  target.scrollTop += 500;
  if (target.scrollTop < 10000) {
    waitForAtLeastOneFrame().then(scroll);
  } else {
    takeScreenshot();
  }
}

waitForAtLeastOneFrame().then(scroll);
</script>