Update references to the extension messaging APIs to point to the "runtime"

chrome/test/data/extensions/api_test/executescript/navigation_race/test.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.
 
 chrome.test.getConfig(function(config) {
   var path = "/files/extensions/test_file.txt";
   var urlA = "http://a.com:" + config.testServer.port + path;
   var urlB = "http://b.com:" + config.testServer.port + path;
   var testTabId;
 
   function onTabUpdated(tabId, changeInfo, tab) {
     if (testTabId == tab.id && tab.status == "complete") {
       chrome.tabs.onUpdated.removeListener(onTabUpdated);
       chrome.tabs.update(tabId, {url: urlB});
       executeCodeInTab(testTabId, function() {
         // Generally, the tab navigation hasn't happened by the time we execute
         // the script, so it's still showing a.com, where we don't have
         // permission to run it.
-        if (chrome.extension.lastError) {
+        if (chrome.runtime.lastError) {
           chrome.test.assertTrue(
-              chrome.extension.lastError.message.indexOf(
+              chrome.runtime.lastError.message.indexOf(
                   'Cannot access contents of url "http://a.com:') == 0);
           chrome.test.notifyPass();
         } else {
           // If there were no errors, then the script did run, but it should
           // have run on on b.com (where we do have permission).
           chrome.tabs.get(tabId, function(tab) {
             chrome.test.assertTrue(
                 tab.title.indexOf("hi, I'm on http://b.com:") == 0);
             chrome.test.notifyPass();
           });
         }
       });
     }
   }
 
   chrome.tabs.onUpdated.addListener(onTabUpdated);
   chrome.tabs.create({url: urlA}, function(tab) {
     testTabId = tab.id;
   });
 });