var _newUA = navigator.userAgent.replace(/ ?Swing\/[0-9.]*/, '');
Object.defineProperty(window.navigator, "userAgent", {
get: function() {return _newUA}
});
// "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.114 Safari/537.36 Swing/2.3.0.0"
함수 호출 후
// "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.114 Safari/537.36"