Function isIOS13

Ports/JavaScriptPort/src/main/webapp/js/fontmetrics.js:2270–2272

()

    	//return (/iPad/.test(navigator.userAgent) && !window.MSStream) ||  (navigator.platform === 'MacIntel' && navigator.maxTouchPoints > 1);
    }    
    function isIOS13() {
    	return isIOS() && "download" in document.createElement("a")
    }
    
    function createAudioContext(desiredSampleRate) {
        var AudioCtor = window.AudioContext || window.webkitAudioContext