Fix issue with the Buy Plan button.

chrome/browser/resources/options2/chromeos/internet_detail.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.
 
 cr.define('options.internet', function() {
   var OptionsPage = options.OptionsPage;
   /** @const */ var ArrayDataModel = cr.ui.ArrayDataModel;
 
   /**
    * Network settings constants. These enums must match their C++
@@ skipping 106 matching lines @@
                                                         function(event) {
         DetailsInternetPage.setDetails();
         DetailsInternetPage.disconnectNetwork();
       });
 
       $('activate-details').addEventListener('click', function(event) {
         DetailsInternetPage.activateFromDetails();
       });
 
       $('buyplan-details').addEventListener('click', function(event) {
-        chrome.send('buyDataPlan', [params.servicePath]);
+        var data = $('connection-state').data;
+        chrome.send('buyDataPlan', [String(data.servicePath)]);
         OptionsPage.closeOverlay();
       });
 
       $('view-account-details').addEventListener('click', function(event) {
         chrome.send('showMorePlanInfo');
         OptionsPage.closeOverlay();
       });
 
       $('cellular-apn-use-default').addEventListener('click', function(event) {
         var data = $('connection-state').data;
@@ skipping 765 matching lines @@
 
     // Don't show page name in address bar and in history to prevent people
     // navigate here by hand and solve issue with page session restore.
     OptionsPage.showPageByName('detailsInternetPage', false);
   };
 
   return {
     DetailsInternetPage: DetailsInternetPage
   };
 });