<!doctype html>
<html>
  <head>
    <title>requestAnimationFrame must be triggered once</title>
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <link rel="help" href="https://w3c.github.io/web-performance/specs/RequestAnimationFrame/Overview.html#dom-windowanimationtiming-requestanimationframe"/>
  </head>
  <body>
    <div id="log"></div>
    <script>
      async_test(function (t) {
        t.step(function() {
          assert_false(document.hidden, "document.hidden must be exist and be false to run this test properly");
        });
        window.requestAnimationFrame(function () {
          t.step(function() { assert_true(true); t.done(); });
        });
      }, "requestAnimationFrame callback is invoked at least once before the timeout");
    </script>
  </body>
</html>