Fix to problem of chrome.runtime sometimes not being defined.

chrome/renderer/resources/extensions/last_error.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.
 
+requireNative('runtime');
+
 function set(message) {
-  var errorObject = { "message": message };
+  var errorObject = { 'message': message };
   if (chrome.extension)
     chrome.extension.lastError = errorObject;
   chrome.runtime.lastError = errorObject;
 };
 
 function clear() {
   if (chrome.extension)
     delete chrome.extension.lastError;
   delete chrome.runtime.lastError;
 };
 
 exports.clear = clear;
 exports.set = set;