promote_img_in_viewport_priority.html

<!DOCTYPE html>
<div style="width: 100%">
   <img style="width: 10px; height: 10px" src="image_slow.pl"/>
   <img style="width: 20px; height: 10px" src="image_slow.pl"/>
</div>
<div style="height: 99999px; width: 100%" id="view_div"></div>
<div style="width: 100%">
  <img style="width: 10px; height: 10px" src="image_slow_out_of_viewport.pl">
</div>
<script>
document.body.offsetTop; // Force a layout.
</script>
<div style="width: 100%">
   <img src="image_slow.pl"/>
</div>
<script>
document.body.offsetTop; // Force a layout.
</script>

chromium/third_party/blink/renderer/core/testing/data/promote_img_in_viewport_priority.html