chromium/third_party/blink/web_tests/paint/float-painted-when-no-longer-self-painting.html

<!DOCTYPE html>
<style>
#header:after{content:'';display:block;clear:both}
#test {float:left;height:70px;overflow:hidden;}
</style>
<p>crbug.com/731044: Ensure float is painted.
<div>
  <div id="header">
    <div>
      <div id="test">
        <span>You should see this text.</span>
      </div>
    </div>
  </div>
</div>
<script>
test.style["opacity"] = .75;
document.body.offsetTop;
test.style["opacity"] = 100;
</script>