<!DOCTYPE html>
<html>
<head>
  <script>
    window.top.postMessage(JSON.stringify({
        "type": "child-sameorigin-loaded",
        "isActive": navigator.userActivation.isActive,
        "hasBeenActive": navigator.userActivation.hasBeenActive
    }), "*");

    window.addEventListener("click", event => {
        window.top.postMessage(JSON.stringify({
            "type": "child-sameorigin-report",
            "isActive": navigator.userActivation.isActive,
            "hasBeenActive": navigator.userActivation.hasBeenActive
        }), "*");
    });
  </script>
</head>
<body style="background: lightgreen;">
  <!-- The midpoint of this frame should be outside the grandchild frame. -->
  <div style="height: 75px;">Same-origin child frame</div>
  <iframe id="child2" width="270px" height="30px"
          src="child-two.html">
  </iframe>
</body>
</html>