magnetometer/support-iframe.html - external/github.com/web-platform-tests/wpt - Git at Google

 <!DOCTYPE HTML>
 <meta charset="utf-8">
 <script>
 try {
   let sensor = new Magnetometer();
   parent.postMessage("sensor.start() can be fired within iframes", '*');
 } catch (e) {
   parent.postMessage(e.name, '*');
 }
 </script>
	<!DOCTYPE HTML>
	<meta charset="utf-8">
	<script>
	try {
	let sensor = new Magnetometer();
	parent.postMessage("sensor.start() can be fired within iframes", '*');
	} catch (e) {
	parent.postMessage(e.name, '*');
	}
	</script>