Allow comments in extension config files.

chrome/common/extensions/api/contextMenus.json

+// 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.
+
 [
   {
     "namespace": "contextMenus",
     "dependencies": [ "tabs" ],
     "types": [
       {
         "id": "OnClickData",
         "type": "object",
         "description": "Information sent when a context menu item is clicked.",
         "properties": {
@@ skipping 223 matching lines @@
             "name": "callback",
             "optional": true,
             "parameters": [],
             "description": "Called when removal is complete."
           }
         ]
       }
     ]
   }
 ]