<!DOCTYPE html>
<h1>file_broadcast_load.html</h1>
<script>
let channel = new BroadcastChannel("test");
channel.onmessage = function(e) {
  console.log("file_broadcast_load.html got message:", e.data);
  if (e.data == "close") {
    window.close();
  }
};

addEventListener("load", function() {
  console.log("file_broadcast_load.html loaded");
  channel.postMessage("load");
});
</script>
