html-background-image-change-size.html

<!DOCTYPE html>
<script src="../resources/text-based-repaint.js"></script>
<style>
html {
  background-image: linear-gradient(blue, blue);
  background-position: center;
  background-repeat: no-repeat;
  background-size: 100px 100px;
  width: 300px;
  height: 300px;
}
</style>
<div style="width: 600px; height: 500px"></div>
<script>
function repaintTest() {
  document.documentElement.style.height = '400px';
}
runRepaintAndPixelTest();
</script>

chromium/third_party/blink/web_tests/paint/invalidation/background/html-background-image-change-size.html