Remove unnecessary XSS check introduced by #2451 (#2679)

* Remove unnecessary XSS check introduced by #2451

* Remove test file of `isValidXss`

lib/helpers/isURLSameOrigin.js

@@ -1,7 +1,6 @@
 'use strict';
 
 var utils = require('./../utils');
-var isValidXss = require('./isValidXss');
 
 module.exports = (
   utils.isStandardBrowserEnv() ?
@@ -22,10 +21,6 @@ module.exports = (
       function resolveURL(url) {
         var href = url;
 
-        if (isValidXss(url)) {
-          throw new Error('URL contains XSS injection attempt');
-        }
-
         if (msie) {
         // IE needs attribute set twice to normalize properties
           urlParsingNode.setAttribute('href', href);

lib/helpers/isValidXss.js

@@ -1,7 +0,0 @@
-'use strict';
-
-module.exports = function isValidXss(requestURL) {
-  var xssRegex = /(\b)(on\w+)=|javascript|(<\s*)(\/*)script/gi;
-  return xssRegex.test(requestURL);
-};
-