<!DOCTYPE html>
<script src="../../resources/run-after-layout-and-paint.js"></script>
<style>
#box, #box-unchanged {
  margin-left: 300px;
  width: 50px;
  height: 50px;
}
#box {
  margin-top: 150px;
  background-color: green;
}
#box-unchanged {
  background-color: blue;
}
#container {
  width: 500px;
  height: 500px;
  backface-visibility: hidden;
  overflow: scroll;
}
</style>
Tests invalidation and painting of a box changing background while composited scrolled.
<div id="container">
<div id="box"></div>
<div id="box-unchanged"></div>
<div style="height: 4000px"></div>
</div>