<style>
  #box {
      position: absolute;
      left: 0;
      top: 0;
      height: 100px;
      width: 100px;
      background-color: red;
      -webkit-animation-name: flip;
      -webkit-animation-duration: 1s;
      -webkit-animation-timing-function: linear;
  }

  @-webkit-keyframes flip {
      from { -webkit-transform: matrix( 1,  0,  0, 1, 0, 0); }
      to   { -webkit-transform: matrix( 1,  0,  0, -1, 0, 0); }
  }

  p {
    position: relative;
    top: 150px;
  }
  #result {
    position: relative;
    top: 200px;
  }
</style>
<script src="resources/animation-test-helpers.js"></script>
<script>
const expectedValues = [
  // [animation-name, time, element-id, property, expected-value, tolerance]
  ["flip", 0.5, "box", "webkitTransform", [1, 0, 0, 0, 0, 0], 0.3],
];

if (window.internals)
    window.internals.settings.setAcceleratedCompositedAnimationsEnabled(false);

runAnimationTest(expectedValues, null, null, true, null, function () {
    if (window.internals)
        window.internals.settings.setAcceleratedCompositedAnimationsEnabled(true);
});
</script>

<div id="box"></div>
<p>
  During the animation, the box should flip in the horizontal axis. It should
  not disappear into a single point (i.e. the visual width should not change).
</p>
<div id="result"></div>