chromium/src/third_party/blink/web_tests/compositing/overflow/relpos-under-abspos-overflow-hidden-opacity.html

<div style="width:10px; height:10px; overflow:hidden;">
  <div style="opacity:0.5;">
    <div style="position:absolute; z-index:0; width:100px; height:100px; border:1px dashed black; overflow:hidden;">
      <div style="position:relative; top:50px; left:50px; width:100px; height:100px; background:red;"></div>
    </div>
  </div>
</div>