Use utils.forEach everywhere rather than Array.prototype.forEach to guard

chrome/renderer/resources/extensions/content_watcher.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.
 
 var contentWatcherNative = requireNative("contentWatcherNative");
+var forEach = require('utils').forEach;
 
-// Returns the indices in |css_selectors| that match any element on the page.
-exports.FindMatchingSelectors = function(css_selectors) {
+// Returns the indices in |cssSelectors| that match any element on the page.
+exports.FindMatchingSelectors = function(cssSelectors) {
   var result = []
-  css_selectors.forEach(function(selector, index) {
+  forEach(cssSelectors, function(index, selector) {
     try {
       if (document.querySelector(selector) != null)
         result.push(index);
     } catch (exception) {
       throw new Error("query Selector failed on '" + selector + "': " +
                       exception.stack);
     }
   });
   return result;
 };
 
 // Watches the page for all changes and calls FrameMutated (a C++ callback) in
 // response.
 var mutation_observer = new WebKitMutationObserver(
   contentWatcherNative.FrameMutated);
 
 // This runs once per frame, when the module is 'require'd.
 mutation_observer.observe(document, {
   childList: true,
   attributes: true,
   characterData: true,
   subtree: true});