background-paint-non-composited-scrolled.html

<!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: yellow;
}
#box-unchanged {
  background-color: blue;
}
#container {
  width: 500px;
  height: 500px;
  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>
<script>

if (window.testRunner)
  testRunner.waitUntilDone();

runAfterLayoutAndPaint(function() {
  var container = document.querySelector('#container');
  var box = document.querySelector("#box");
  container.scrollTop = 180;
  box.style.backgroundColor = "green";
  runAfterLayoutAndPaint(function() {
    container.scrollTop = 0;
    if (window.testRunner)
      testRunner.notifyDone();
  });
});

</script>

chromium/third_party/blink/web_tests/fast/scrolling/background-paint-non-composited-scrolled.html