third_party/blink/web_tests/fast/css/long-selector-list-assert.html - chromium/src - Git at Google

 <!DOCTYPE html>
 <script>
     if (window.testRunner)
         testRunner.dumpAsText();

     var selector = "";
     for (var i=0; i<4096; i++)
         selector += "#id" + i + ", ";
     selector += "#assert ";
     var stylesheet = "<style>" + selector + "{ color: pink }</style>";
     document.write(stylesheet);
 </script>
 <p>PASS if no crash or assert.</p>
	<!DOCTYPE html>
	<script>
	if (window.testRunner)
	testRunner.dumpAsText();

	var selector = "";
	for (var i=0; i<4096; i++)
	selector += "#id" + i + ", ";
	selector += "#assert ";
	var stylesheet = "<style>" + selector + "{ color: pink }</style>";
	document.write(stylesheet);
	</script>
	<p>PASS if no crash or assert.</p>