LayoutTests/http/tests/intersection-observer/resources/intermediate-frame.html - WebKit - Git at Google

 <!DOCTYPE html>
 <style>
 iframe {
   width: 200px;
   height: 300px;
 }

 #scroller {
   width: 250px;
   height: 100px;
   overflow: scroll;
 }
 </style>

 <div id="scroller">
     <iframe id="nestedFrame" src="nested-frame.html"></iframe>
 </div>
	<!DOCTYPE html>
	<style>
	iframe {
	width: 200px;
	height: 300px;
	}

	#scroller {
	width: 250px;
	height: 100px;
	overflow: scroll;
	}
	</style>

	<div id="scroller">
	<iframe id="nestedFrame" src="nested-frame.html"></iframe>
	</div>