chromium/third_party/blink/web_tests/animations/3d/matrix-transform-type-animation.html

<!DOCTYPE html>
<html>
<head>
  <style type="text/css">
    .container {
      position: relative;
      height: 100px;
    }
    .box {
      position: absolute;
      left: 0;
      top: 0;
      height: 100px;
      width: 100px;
      background-color: green;
    }
    
    #indicator {
      position: absolute;
      top: 0;
      left: 50px;
      background-color: red;
    }
    
    #box {
      animation: anim 10s linear;
    }
    
    @keyframes anim {
        from { transform: matrix(1, 0, 0, 1, 100, 0); }
        to   { transform: matrix(1, 0, 0, 1, -400, 0); }
    }
  </style>
  <script src="../resources/animation-test-helpers.js" type="text/javascript"></script>
  <script type="text/javascript">
    const expectedValues = [
      // [time, element-id, property, expected-value, tolerance]
      [1, "box",  "webkitTransform.4", 50, 2],
    ];
    
    var pixelTest = true;
    var disablePauseAPI = false;
    runAnimationTest(expectedValues, null, null, disablePauseAPI, pixelTest);
  </script>
</head>
<body>

<!-- In the pixel result, the green box should obscure the red box. -->
<div class="container">
  <div id="indicator" class="box"></div>
  <div class="box" id="box"></div>
</div>

<div id="result"></div>
</body>
</html>