title: Webkit-mask-size not working
body: <p>I'm trying to use webkit-mask-size to make a mask image smaller. Like this:</p>
  
  <pre><code>.myClass {
      width: 100%;
      height: 100%;
      background: #ffffff;
      -webkit-mask-size: 50% 50%;
      -webkit-mask: url(../css/images/myimage.png) center center;
  }
  </code></pre>
  
  <p>The div which has myClass applied to it has a parent container which has a fixed height set on it. </p>
  
  <p>Whatever I set -webkit-mask-size to it makes no difference.</p>