chromium/third_party/blink/web_tests/external/wpt/css/css-position/sticky/position-sticky-fractional-offset.html

<!DOCTYPE html>
<html class="reftest-wait">
<link rel="help" href="https://www.w3.org/TR/css-position-3/#sticky-pos" />
<meta name="assert" content="Position sticky with a fractional offset should not show a gap" />
<link rel="match" href="position-sticky-fractional-offset-ref.html" />

<style>
  .sticky-container {
    width: 100px;
    height: 100px;
    overflow-y: scroll;
    background: red;
    display: inline-block;
  }

  .sticky {
    position: sticky;
    top: 0;
    height: 50px;
    background: lightgreen;
  }

  .force-scroll {
    height: 300px;
    background: lightgreen;
  }
</style>

<div class="sticky-container">
  <div style="height: 10.10px;"></div>
  <div class="sticky"></div>
  <div class="force-scroll"></div>
</div>

<div class="sticky-container">
  <div style="height: 10.25px;"></div>
  <div class="sticky"></div>
  <div class="force-scroll"></div>
</div>

<div class="sticky-container">
  <div style="height: 10.50px;"></div>
  <div class="sticky"></div>
  <div class="force-scroll"></div>
</div>

<div class="sticky-container">
  <div style="height: 10.75px;"></div>
  <div class="sticky"></div>
  <div class="force-scroll"></div>
</div>

<div class="sticky-container">
  <div style="height: 10.90px;"></div>
  <div class="sticky"></div>
  <div class="force-scroll"></div>
</div>

<script>
  window.onload = function() {
    // Start with all containers scrolled to the top.
    var containers = document.getElementsByClassName('sticky-container');
    for (let i = 0; i < containers.length; i++) {
      containers[i].scrollTo(0, 0);
    }

    // Wait for a full frame, then scroll all containers down so the sticky
    // elements are stuck to the container. There should be no visible gap
    // where the container's red background color is visible.
    requestAnimationFrame(() => {
      requestAnimationFrame(() => {
        for (let i = 0; i < containers.length; i++) {
          containers[i].scrollTo(0, 20);
        }
        document.documentElement.classList.remove('reftest-wait');
      });
    });
  };
</script>
</html>