chromium/third_party/blink/web_tests/http/tests/intersection-observer/cross-origin-display-none.html

<!DOCTYPE html>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>

<style>
pre, #log {
  position: absolute;
  top: 0;
  left: 200px;
}
iframe {
  width: 300px;
  height: 150px;
  border: none;
}
</style>

<iframe src="http://localhost:8080/intersection-observer/resources/cross-origin-display-none-subframe.html"></iframe>

<script>
function waitForFrame(t, f) {
  requestAnimationFrame(function() {
    t.step_timeout(f, 0);
  });
}

async_test(
function(t) {
  let iframe = document.querySelector("iframe");

  // When an iframe is cross-origin, as in this test, it will not run
  // lifecycle updates while it's not visible. In that case, we can't use
  // requestAnimationFrame to wait for IntersectionObserver to run.

  function step0(event) {
    assert_equals(event.data,"");
    this.properties.raf = true;
  }

  function step1(event) {
    iframe.style.display = "none";
    assert_equals(JSON.stringify(event.data),
                  JSON.stringify([true]),
                  'First notification');
    // No raf for cross-origin iframe.
    this.properties.raf = false;
  }

  function step2(event) {
    iframe.style.display = "";
    assert_equals(JSON.stringify(event.data),
                  JSON.stringify([false]),
                  'iframe.style.display = "none"');
    this.properties.raf = true;
  }

  function step3(event) {
    iframe.style.visibility = "hidden";
    assert_equals(JSON.stringify(event.data),
                  JSON.stringify([true]),
                  'iframe.style.display = ""');
    // No raf for cross-origin iframe.
    this.properties.raf = false;
  }

  function step4(event) {
    iframe.style.visibility = "";
    assert_equals(JSON.stringify(event.data),
                  JSON.stringify([false]),
                  'iframe.style.visibility = "hidden"');
  }

  let steps = [step0, step1, step2, step3, step4];

  window.addEventListener("message", event => {
    if (steps.length) {
      t.step(steps.shift().bind(t, event));
      waitForFrame(t, () => {
        iframe.contentWindow.postMessage({raf: t.properties.raf}, "*");
      });
    } else {
      t.done();
    }
  });
},
"Intersection observer V2: test display and visibility CSS properties applied to iframe",
{raf: null});
</script>