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

chrome/renderer/resources/extensions/runtime_custom_bindings.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.
 
 // Custom bindings for the runtime API.
 
 var runtimeNatives = requireNative('runtime');
 var extensionNatives = requireNative('extension');
 var GetExtensionViews = extensionNatives.GetExtensionViews;
 var OpenChannelToExtension = runtimeNatives.OpenChannelToExtension;
@@ skipping 29 matching lines @@
 
   apiFunctions.setHandleRequest('sendMessage',
                                 function(targetId, message, responseCallback) {
     var port = chrome.runtime.connect(targetId || chrome.runtime.id,
         {name: chromeHidden.kMessageChannel});
     chromeHidden.Port.sendMessageImpl(port, message, responseCallback);
   });
 
   apiFunctions.setHandleRequest('sendNativeMessage',
                                 function(targetId, message, responseCallback) {
-    var port = chrome.extension.connectNative(
+    var port = chrome.runtime.connectNative(
         targetId, message, chromeHidden.kNativeMessageChannel);
     chromeHidden.Port.sendMessageImpl(port, '', responseCallback);
   });
 
   apiFunctions.setUpdateArgumentsPreValidate('connect', function() {
     // Align missing (optional) function arguments with the arguments that
     // schema validation is expecting, e.g.
     //   runtime.connect()   -> runtime.connect(null, null)
     //   runtime.connect({}) -> runtime.connect(null, {})
     var nextArg = 0;
@@ skipping 67 matching lines @@
   apiFunctions.setCustomCallback('getBackgroundPage',
                                  function(name, request, response) {
     if (request.callback) {
       var bg = GetExtensionViews(-1, 'BACKGROUND')[0] || null;
       request.callback(bg);
     }
     request.callback = null;
   });
 
 });