<html>
<head>
  <script>
  if (window.testRunner) {
    testRunner.dumpAsText();
  }
  </script>
  <style>
  @-webkit-keyframes anim {
    42% {
      -webkit-border-horizontal-spacing: 42rem;
    }
  }
  body::first-letter {
    -webkit-animation-name: anim;
  }
  </style>
</head>
<body>
This test passes if it does not crash.
</body>
</html>