subpixel-overflow-mouse-drag.html | Explore in Territory

<!DOCTYPE html>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="../../resources/gesture-util.js"></script>
<style>
body {
  zoom: 175%;
  margin: 0;
}
#container {
  overflow-y: scroll;
  width: 200px;
  height: 200px;
}
#content {
  background-color: green;
  width: 100px;
  height: 200.3px;
}
</style>
<div id="container">
  <div id="content"></div>
</div>
<script>
  onload = function() {
    promise_test(async t => {
      await waitForCompositorCommit();

      var container = document.getElementById('container');
      eventSender.mouseMoveTo(340, 200);
      eventSender.mouseDown();
      eventSender.mouseMoveTo(340, 250);
      eventSender.mouseUp();

      var expectedScrollTop = 0.57;
      var tolerance = 0.02;
      await waitFor(() => {
        return Math.abs(container.scrollTop - expectedScrollTop) <= tolerance;
      });
    }, "Subpixel scrollbar thumb is dragged by mouse.");
  };
</script>

chromium/third_party/blink/web_tests/fast/scrolling/subpixel-overflow-mouse-drag.html