hover-create-scrollbar-part-expected.html

<!DOCTYPE html>
<style>
  ::-webkit-scrollbar { background-color: green; }
</style>
For manual test, move mouse over the red bar.
The test passes if the bar turns green on mouse over and red on mouse out.
<div style="width: 200px; height: 200px; overflow-y: scroll" id="scroller">
  <div style="height: 500px"></div>
</div>

chromium/third_party/blink/web_tests/paint/invalidation/scroll/hover-create-scrollbar-part-expected.html