chromium/third_party/blink/web_tests/fast/reflections/opacity-reflection-transform.html

<!DOCTYPE>
<html>
  <head>
    <style type="text/css" media="screen">
      .box {
        width: 100px;
        height: 100px;
      }

      .alpha {
        margin: 20px 100px;
        opacity: 0.9;
        border: 1px solid black;
      }
      
      .reflected {
        width: 200px;
        background-color: green;
        -webkit-transform-origin: top left;
        transform: rotate(20deg);
        -webkit-box-reflect: right 20px;
      }
      
    </style>
  </head>

  <p>Test that opacity doesn't cause clipping of transformed, reflected content. You should see a rotated green box and its full reflection.</p>
  <div class="alpha box">
    <div class="reflected box">
    </div>
  </div>
</html>