[ChromeOS] Pass optional email to auth extension.

chrome/browser/resources/chromeos/login/screen_gaia_signin.js

 // Copyright (c) 2011 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.
 
 /**
  * @fileoverview Oobe signin screen implementation.
  */
 
 cr.define('login', function() {
 
@@ skipping 65 matching lines @@
     },
 
     /**
      * Event handler that is invoked just before the frame is shown.
      * @param data {string} Screen init payload. Url of auth extension start
      *        page.
      */
     onBeforeShow: function(data) {
       console.log('Opening extension: ' + data.startUrl +
                   ', opt_email=' + data.email);
+
       var frame = $('signin-frame');
       frame.addEventListener('load', function(e) {
         console.log('Frame loaded: ' + data.startUrl);
       });
-      frame.contentWindow.location.href = data.startUrl;
-      this.extension_url_ = data.startUrl;
-      // TODO(xiyuan): Pre-populate Gaia with data.email (if any).
+
+      var params = [];
+      if (data.hl)
+        params.push('hl=' + encodeURIComponent(data.hl));
+      if (data.email)
+        params.push('email=' + encodeURIComponent(data.email));
+
+      var url = data.startUrl;
+      if (params.length)
+        url += '?' + params.join('&');
+
+      frame.contentWindow.location.href = url;
+      this.extension_url_ = url;
 
       $('createAccount').hidden = !data.createAccount;
       $('guestSignin').hidden = !data.guestSignin;
 
       this.loading = true;
     },
 
     /**
      * Checks if message comes from the loaded authentication extension.
      * @param e {object} Payload of the received HTML5 message.
@@ skipping 27 matching lines @@
       // Reload and show the sign-in UI if needed.
       if (takeFocus)
         Oobe.showSigninUI();
     }
   };
 
   return {
     GaiaSigninScreen: GaiaSigninScreen
   };
 });