<!DOCTYPE html>
<html>
<body>
<p>This test passes if it doesn't crash.</p>
<div id="testDiv"></div>
<script>
if (window.testRunner)
  testRunner.dumpAsText();

testDiv.style.cssText += "-webkit-mask-position: 0px 0px, 1px 1px";
testDiv.style.cssText += "-webkit-mask-position: 1px 1px;";
</script>
</body>
</html>