<!DOCTYPE html> <html class="reftest-wait"> <script> var context = new window.OfflineAudioContext(1, 256, 48000); var analyser = context.createAnalyser(); analyser.channelCount = 2; analyser.channelCountMode = "explicit"; analyser.fftSize = 32; var source = context.createOscillator(); source.connect(analyser); source.start(0); context.startRendering(). then(function() { document.documentElement.removeAttribute("class"); }); </script>