<!DOCTYPE html> <html class="reftest-wait"> <head> <script> function boom() { var ac = new window.AudioContext("publicnotification"); setTimeout(function() { document.documentElement.removeAttribute("class"); var htmlAudio = new Audio(); var stream = htmlAudio.mozCaptureStreamUntilEnded(); ac.createMediaStreamSource(stream); }, 0); } </script> </head> <body onload="boom();"> </body> </html>