in src/common/pluginloader.js [26:34]
exports.injectScript = function (url, onload, onerror) {
var script = document.createElement('script');
// onload fires even when script fails loads with an error.
script.onload = onload;
// onerror fires for malformed URLs.
script.onerror = onerror;
script.src = url;
document.head.appendChild(script);
};