LayoutTests/media/video-source-before-src.html - WebKit - Git at Google

 <html>
 <head>
 <script src=video-test.js></script>
 <script>

 if (window.testRunner) {
     internals.settings.setVideoPlaybackRequiresUserGesture(true);
     testRunner.waitUntilDone();
     testRunner.dumpAsText();
 }

 var video

 window.onload = () => {
     video = document.getElementsByTagName("video")[0];
     var source = document.createElement("source");
     source.src = "source.mp4";
     video.appendChild(source);
     video.src = "src.mp4";

     setTimeout(()=>{
         testExpected("relativeURL(video.currentSrc)", "");
         if (window.testRunner)
             testRunner.notifyDone();
     }, 1);
 }

 </script>
 </head>
 <body>
 Append source element before setting src attribute.<br>
 Platforms that support setVideoPlaybackRequiresUserGesture
 will have the expected, empty, currentSrc. Platforms that don't should
 have the unexpected "src.mp4".<br>
 <video width=320 height=240></video>
 </body>
 </html>
	<html>
	<head>
	<script src=video-test.js></script>
	<script>

	if (window.testRunner) {
	internals.settings.setVideoPlaybackRequiresUserGesture(true);
	testRunner.waitUntilDone();
	testRunner.dumpAsText();
	}

	var video

	window.onload = () => {
	video = document.getElementsByTagName("video")[0];
	var source = document.createElement("source");
	source.src = "source.mp4";
	video.appendChild(source);
	video.src = "src.mp4";

	setTimeout(()=>{
	testExpected("relativeURL(video.currentSrc)", "");
	if (window.testRunner)
	testRunner.notifyDone();
	}, 1);
	}

	</script>
	</head>
	<body>
	Append source element before setting src attribute.<br>
	Platforms that support setVideoPlaybackRequiresUserGesture
	will have the expected, empty, currentSrc. Platforms that don't should
	have the unexpected "src.mp4".<br>
	<video width=320 height=240></video>
	</body>
	</html>