chromium/third_party/blink/web_tests/animations/unanimated-style.html

<!DOCTYPE html>

<html>
<head>
    <style type="text/css" media="screen">
        .box {
            position: absolute;
            height: 100px;
            width: 100px;
            left: 0px;
            background-color: blue;
        }

        .box.animating {
            animation: move 1s linear;
            left: 400px;
        }

        @keyframes move {
            from {
            }
            to   {
                left: 500px;
            }
        }

        #result {
            margin-top: 130px;
        }
    </style>
    <script src="resources/animation-test-helpers.js" type="text/javascript" charset="utf-8"></script>
    <script type="text/javascript" charset="utf-8">

      if (window.testRunner)
        testRunner.waitUntilDone();

      const expectedValues = [
        // [time, element-id, property, expected-value, tolerance]
        [0.5, "test", "left", 450, 0],
      ];

      function setupTest()
      {
        test.offsetTop; // force style recalc
        test.className = 'animating box';
        runAnimationTest(expectedValues);
      }

      window.addEventListener('load', setupTest, false);

    </script>
</head>
<body>
    <p>Box should animate from left of 400px to 500px.</p>
    <div id="test" class="box"></div>
    <div id="result"></div>
</body>
</html>