chromium/third_party/blink/web_tests/animations/timing/keyframe-timing-functions.html

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">

<html lang="en">
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  <title>Keyframe Timing Functions</title>
  <style type="text/css" media="screen">
  
    #container {
      position: relative;
      border: 1px solid black;
      height: 100px;
      width: 700px;
    }
    
    #box {
      position: absolute;
      height: 100px;
      width: 100px;
      background-color: blue;
      animation-name: move;
      animation-duration: 1.5s;
    }

    @keyframes move {
      0%   {
        left: 0;
        animation-timing-function: linear;
      }
      100% {
        left: 600px;
      }
    }
    
  </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]
      [0.75, "box", "left", 300, 20],
    ];
    
    runAnimationTest(expectedValues);
  </script>
</head>
<body>

<div id="container">
    This test should do a linear animation. The timing-function comes from the keyframe, so this is testing
    whether or not the timing function in keyframes is used.
  <div id="box"></div>
</div>
<div id="result">
</div>
</body>
</html>