cros: Restrict gaiaURL to be http and https only.

chrome/browser/resources/gaia_auth/util.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * Alias for document.getElementById.
  * @param {string} id The ID of the element to find.
  * @return {HTMLElement} The found element or null if not found.
  */
 function $(id) {
@@ skipping 54 matching lines @@
 /**
  * Extract domain name from an URL.
  * @param {string} url An URL string.
  * @return {string} The host name of the URL.
  */
 function extractDomain(url) {
   var a = document.createElement('a');
   a.href = url;
   return a.hostname;
 }
+
+/**
+ * Extract protocol from an URL.
+ * @param {string} url An URL string.
+ * @return {string} The protocol of the URL.
+ */
+function extractProtocol(url) {
+  var a = document.createElement('a');
+  a.href = url;
+  return a.protocol;
+}
+