stacktrace-gps.js
function _xdr(url) {
        return new Promise(function(resolve, reject) {
            var req = new XMLHttpRequest();
            req.open('get', url);
            req.onerror = reject;
            req.onreadystatechange = function onreadystatechange() {
                if (req.readyState === 4) {
                    if ((req.status >= 200 && req.status < 300) ||
                        (url.substr(0, 7) === 'file://' && req.responseText)) {
                        resolve(req.responseText);
                    } else {
                        reject(new Error('HTTP status: ' + req.status + ' retrieving ' + url));
                    }
                }
            };
            req.send();
        });

    }
function _xdr(url) {
        return new Promise(function(resolve, reject) {
            var req = new XMLHttpRequest();
            req.open('get', url);
            req.onerror = reject;
            req.onreadystatechange = function onreadystatechange() {
                if (req.readyState === 4) {
                    if ((req.status >= 200 && req.status < 300) ||
                        (url.substr(0, 7) === 'file://' && req.responseText)) {
                        resolve(req.responseText);
                    } else {
                        reject(new Error('HTTP status: ' + req.status + ' retrieving ' + url));
                    }
                }
            };
            req.send();
        });

    }
function _xdr ( url ) { return new Promise ( function ( resolve , reject ) { var req = new XMLHttpRequest ( ) ; req . open ( 'get' , url ) ; req . onerror = reject ; req . onreadystatechange = function onreadystatechange ( ) { if ( req . readyState === 4 ) { if ( ( req . status >= 200 && req . status < 300 ) || ( url . substr ( 0 , 7 ) === 'file://' && req . responseText ) ) { resolve ( req . responseText ) ; } else { reject ( new Error ( 'HTTP status: ' + req . status + ' retrieving ' + url ) ) ; } } } ; req . send ( ) ; } ) ; }
Make a X-Domain request to url and callback.

@param {String} url
@returns {Promise} with response text if fulfilled
Make a X - Domain request to url and callback .