LayoutTests/fast/repaint/float-box-appears-and-no-inline-content.html

<style>
.container {
  width: 100px;
  height: 45px;
  font-size: 10px;
  background-color: green;
}

#floater {
  float: left;
  width: 50px;
  height: 45px;
  background-color: blue;
  display: none;
}
</style>
<div class=container><div id=floater></div></div>
<pre id=repaints></pre>
<script src="../../resources/ui-helper.js"></script>
<script>
if (window.testRunner) {
  testRunner.dumpAsText();
  testRunner.waitUntilDone();
}
async function runTest() {
  await UIHelper.renderingUpdate();

  if (window.internals)
    internals.startTrackingRepaints();

  floater.style.display = "block";

  await UIHelper.renderingUpdate();

  if (window.internals) {
    repaints.innerHTML = window.internals.repaintRectsAsText();
    internals.stopTrackingRepaints();
  }

  if (window.testRunner)
    testRunner.notifyDone();
}

window.addEventListener('load', runTest);
</script>