<!doctype HTML>

<!--
Runs an acquireDisplayLock, which appends the first child and schedules a
continuation, which in turn appends the second child.
-->

<style>
#container {
  contain: content;
  width: 150px;
  height: 150px;
  background: lightblue;
}
#child1 {
  width: 50px;
  height: 50px;
  background: lightgreen;
}
#child2 {
  width: 50px;
  height: 50px;
  background: lightyellow;
}
</style>

<div id="log"></div>

<script>
if (window.testRunner)
  window.testRunner.waitUntilDone();

function createChild(id) {
  let child = document.createElement("div");
  child.id = id;
  return child;
}

function addChild2(context) {
  context.lockedElement.appendChild(createChild("child2"));
}

function addChild1(context) {
  context.lockedElement.appendChild(createChild("child1"));
  context.schedule(addChild2);
}

function finishTest(status_string) {
  if (document.getElementById("log").innerHTML === "")
    document.getElementById("log").innerHTML = status_string;
  if (window.testRunner)
    window.testRunner.notifyDone();
}

function acquire() {
  let container = document.createElement("div");
  container.id = "container";
  container.acquireDisplayLock(addChild1).then(
    () => { finishTest("PASS"); },
    () => { finishTest("FAIL"); });
  document.body.appendChild(container);
}

window.onload = acquire;
</script>