<!DOCTYPE html>
<style type="text/css" media="screen">
  .box {
    height: 100px;
    width: 10000000px; /* Choose a huge width to make the mask excessively large. */
    margin: 20px;
    margin-bottom: 120px;
    background-color: green;
  }
  
  .reflected {
    -webkit-box-reflect: below 2px linear-gradient(transparent, white);
  }

  .composited {
    will-change: transform;
  }
</style>
<p>Reflection should be masked with gradient.</p>
<div class="reflected composited box">
</div>
Passes if it does not crash.
<script>
if (testRunner)
  testRunner.dumpAsText();
</script>