<!DOCTYPE html> <!-- webkit-test-runner [ AsyncOverflowScrollingEnabled=true ] -->

<style>
::-webkit-scrollbar {
  background: red;
}

#item {
  width: 0;
  height: 100px;
  overflow: auto;
}

#child {
  height: 200px;
}
</style>

<div id="item">
  <div id="child">
  </div>
</div>