chromium/third_party/blink/web_tests/external/wpt/webmessaging/Channel_postMessage_with_transfer_outgoing_messages.any.js

async_test(function(t) {
  var channel1 = new MessageChannel();
  var channel2 = new MessageChannel();
  var channel3 = new MessageChannel();
  channel2.port2.onmessage = t.step_func(function (evt) {
    evt.ports[0].postMessage("Second");
    evt.ports[0].postMessage("Third");
    channel3.port1.onmessage = t.step_func(function (evt) {
      evt.ports[0].postMessage("Fourth");
    });
    channel3.port2.postMessage("2", evt.ports);
  });
  channel1.port1.postMessage("First");
  channel2.port1.postMessage("1", [channel1.port1]);
  var counter = 0;
  channel1.port2.onmessage = t.step_func(function (evt) {
    if (counter == 0) {
      assert_equals(evt.data, "First");
      counter = 1;
    } else if (counter == 1) {
      assert_equals(evt.data, "Second");
      counter = 2;
    }
    else if (counter == 2) {
      assert_equals(evt.data, "Third");
      counter = 3;
    }
    else if (counter == 3) {
      assert_equals(evt.data, "Fourth");
      t.done();
    }
  });
}, `When transferring a port,
    outgoing messages sent at each transfer step are received in order by the entangled port.`);