Allow comments in extension config files.

chrome/common/extensions/api/experimental.app.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":"experimental.app",
     "functions": [
       {
         "name": "notify",
         "type": "function",
         "description": "Creates a notification from this app.",
         "parameters": [
           {
@@ skipping 119 matching lines @@
             "name": "callback",
             "optional": true,
             "description": "A callback when the function is complete. Any errors will be reported in <a href='extension.html#property-lastError'>chrome.extension.lastError</a>.",
             "parameters": []
           }
         ]
       }
     ]
   }
 ]