LayoutTests/media/video-controls-to-not-scroll-page-on-load.html - WebKit - Git at Google

 <!DOCTYPE html>
 <html>
 <body onload="testScroll()">
 <div style="width: 256px; height: 2096px; background-color: blue"></div> <!-- Dummy content to help make the page scrollable vertically. -->
 <video src="non-existent.mov" style="width: 256px; height: 256px; background-color: yellow">
     <track src="non-existent.vtt" kind="captions"></track>
 </video>

 <div id="result">FAILED: Test did not run.</div>

 <script>

 if (window.testRunner) {
     testRunner.dumpAsText();
     testRunner.waitUntilDone();
 }

 var result = document.getElementById("result");

 result.innerHTML = "";

 function testScroll () {
 	result.innerHTML += (document.body.scrollTop <= 0)? `PASS`: `FAILED: ${document.body.scrollTop} > 0, the page scrolled automatically.`;

 	testRunner.notifyDone();
 }
 </script>
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<body onload="testScroll()">
	<div style="width: 256px; height: 2096px; background-color: blue"></div> <!-- Dummy content to help make the page scrollable vertically. -->
	<video src="non-existent.mov" style="width: 256px; height: 256px; background-color: yellow">
	<track src="non-existent.vtt" kind="captions"></track>
	</video>

	<div id="result">FAILED: Test did not run.</div>

	<script>

	if (window.testRunner) {
	testRunner.dumpAsText();
	testRunner.waitUntilDone();
	}

	var result = document.getElementById("result");

	result.innerHTML = "";

	function testScroll () {
	result.innerHTML += (document.body.scrollTop <= 0)? `PASS`: `FAILED: ${document.body.scrollTop} > 0, the page scrolled automatically.`;

	testRunner.notifyDone();
	}
	</script>
	</body>
	</html>