<!DOCTYPE html>
<html>
<head>
<script>
function ownerWindow()
{
    var owner = window.parent;
    if (owner === this)
        owner = window.opener;
    return owner;
}

function receiveMessage(messageEvent)
{
    if (messageEvent.source !== ownerWindow())
        ownerWindow().postMessage(messageEvent.data, "*"); // Forward to owner
    else {
        // From owner
        if (messageEvent.data === "new-window")
            window.open("referrer-policy-postmessage.php");
        else if (messageEvent.data === "new-subframe") {
            var subframe = document.createElement("iframe");
            subframe.src = "referrer-policy-postmessage.php";
            document.body.appendChild(subframe);
        }
    }
}

window.addEventListener("message", receiveMessage, false);
ownerWindow().postMessage("ready", "*");
</script>
</head>
</html>