<!DOCTYPE html>
<!--
  Issue ####### repro
  This is a cross-origin iframe for codepen.io/mustaqahmed/####
-->
<h2>Cross-origin subframe</h2>
<div><input id="button" type="button" value="Click here once" /></div>
<div>Green background indicates active transient user activation state.</div>
<script>
  function refreshBackgroundColor() {
    if (!navigator.userActivation)
      return;
    document.body.style.backgroundColor =
        navigator.userActivation.isActive ? "#d0ffd0" : "white";
  }

  function init(label) {
    setInterval(refreshBackgroundColor, 100);
    document.getElementById("button").onclick =
        () => parent.postMessage("click-in-iframe", "*");
  }

  init();
</script>

Add subfrmae src for iframe.src activation bug.
Add subfrmae src for iframe.src activation bug.
