third_party/blink/web_tests/paint/invalidation/paint-invalidation-with-opacity.html - chromium/src - Git at Google

 <!DOCTYPE html>
 <div id="target" style="width: 100px; height: 100px; background: lightblue"></div>
 <script src="resources/text-based-repaint.js"></script>
 <script>
 function repaintTest() {
     document.getElementById('target').style.opacity = 0.5;
 }
 runRepaintAndPixelTest();
 </script>
	<!DOCTYPE html>
	<div id="target" style="width: 100px; height: 100px; background: lightblue"></div>
	<script src="resources/text-based-repaint.js"></script>
	<script>
	function repaintTest() {
	document.getElementById('target').style.opacity = 0.5;
	}
	runRepaintAndPixelTest();
	</script>