Allow comments in extension config files.

chrome/common/extensions/api/pageCapture.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": "pageCapture",
     "functions": [
       {
         "name": "saveAsMHTML",
         "type": "function",
         "description": "Saves the content of the tab with given id as MHTML.",
         "parameters": [
           {
@@ skipping 18 matching lines @@
                 "optional": "true",
                 "description": "The MHTML data as a Blob."
               }
             ]
           }
         ]
       }
     ]
   }
 ]