chromium/third_party/blink/web_tests/animations/timing/missing-keyframe-properties-timing-function.html

<!DOCTYPE html>
<html>
<head>
  <style type="text/css" media="screen">
    .box {
      position: relative;
      margin: 10px;
      left: 0;
      width: 100px;
      height: 100px;
      background-color: blue;
      animation-duration: 2s;
      animation-timing-function: ease-in;
    }
    
    #box1 {
      animation-name: move;
    }
    @keyframes move {
        from {
          opacity: 0;
          left: 100px;
        }
        25% {
          opacity: 0.25;
        }
        50% {
          left: 200px;
          animation-timing-function: linear;
        }
        to {
          left: 400px;
        }
    }

    #box2 {
      animation-name: move2;
    }
    @keyframes move2 {
        from {
          opacity: 0;
          transform: translateX(100px);
        }
        25% {
          opacity: 0.25;
        }
        50% {
          transform: translateX(200px);
          animation-timing-function: linear;
        }
        to {
          transform: translateX(400px);
        }
    }

  </style>
  <script src="../resources/animation-test-helpers.js" type="text/javascript" charset="utf-8"></script>
  <script type="text/javascript" charset="utf-8">
    
    const expectedValues = [
      // [time, element-id, property, expected-value, tolerance]
      [0.5, "box1", "left", 132, 15],
      [0.5, "box2", "transform.4", 132, 15],
      [1.5, "box1", "left", 300, 15],
      [1.5, "box2", "transform.4", 300, 15],
    ];
    
    runAnimationTest(expectedValues);
  </script>
</head>
<body>
<div id="box1" class="box"></div>
<div id="box2" class="box"></div>
<div id="result">
</div>
</body>
</html>