chromium/src/third_party/blink/web_tests/fast/multicol/span/becomes-spanner-with-new-width.html - manifest_repos/chromium_src - Git at Google

 <!DOCTYPE html>
 <p>There should be a green square below, and no red.</p>
 <div id="root" style="column-fill:auto; width:300px; height:300px; background:red;">
     <div style="width:100px;">
         <div style="column-span:all; height:300px; background:green;" data-expected-width="300"></div>
     </div>
 </div>
 <script src="../../../resources/check-layout.js"></script>
 <script>
     document.body.offsetTop;
     document.getElementById("root").style.columns = "2";
     checkLayout("#root");
 </script>
	<!DOCTYPE html>
	<p>There should be a green square below, and no red.</p>
	<div id="root" style="column-fill:auto; width:300px; height:300px; background:red;">
	<div style="width:100px;">
	<div style="column-span:all; height:300px; background:green;" data-expected-width="300"></div>
	</div>
	</div>
	<script src="../../../resources/check-layout.js"></script>
	<script>
	document.body.offsetTop;
	document.getElementById("root").style.columns = "2";
	checkLayout("#root");
	</script>