chromium/third_party/blink/web_tests/external/wpt/css/css-animations/animation-direction-001-manual.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Animations Test: animation-direction - alternate</title>
<link rel="author" title="Nokia Inc." href="http://www.nokia.com">
<link rel="author" title="Intel" href="http://www.intel.com">
<link rel="reviewer" title="Zhiqiang Zhang" href="mailto:[email protected]"> <!-- 2015-03-24 -->
<link rel="help" href="https://drafts.csswg.org/css-animations-1/#animation-direction">
<link rel="help" href="https://drafts.csswg.org/css-animations-1/#animation-name">
<link rel="help" href="https://drafts.csswg.org/css-animations-1/#animation-duration">
<link rel="help" href="https://drafts.csswg.org/css-animations-1/#animation-iteration-count">
<meta name="flags" content="animated">
<meta name="assert" content="When animation-direction is set to alternate,
                             animation cycle will iteration that are
                             odd counts are played in the normal direction,
                             and the animation cycle iterations that are
                             even counts are played in a reverse direction.">
<style>
  div {
    animation-name: sample;
    animation-duration: 10s;
    animation-direction: alternate;
    animation-iteration-count: infinite;

    background-color: blue;
    height: 100px;
    width: 100px;
    position: relative;
  }

  @keyframes sample {
    from {
      left: 150px;
    }
    to {
      left: 0px;
    }
  }
</style>
<body>
  <p>
    Test passes if there is a filled blue square with 'Filler Text',
    which starts moving from right to left on the page load,
    and then moves from left to right. This cycle gets repeated.
  </p>
  <div>Filler Text</div>
</body>