LayoutTests/fullscreen/resources/full-screen-iframe-with-mixed-allow-webkitallow-iframe1.html

iframe1
<iframe allowfullscreen src="full-screen-iframe-with-mixed-allow-webkitallow-iframe2.html">
</iframe>
<script>
window.onmessage = function (messageEvent) {
    parent.postMessage(messageEvent.data, "*");
}
</script>