Allow comments in extension config files.

chrome/common/extensions/api/history.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": "history",
     "types": [
       {
         "id": "HistoryItem",
         "type": "object",
         "description": "An object encapsulating one result of a history query.",
         "properties": {
           "id": {"type": "string", "minimum": 0, "description": "The unique identifier for the item."},
@@ skipping 144 matching lines @@
             "properties": {
               "allHistory": { "type": "boolean", "description": "True if all history was removed.  If true, then urls will be empty." },
               "urls": { "type": "array", "items": { "type": "string" }, "optional": true}
             }
           }
         ]
       }
     ]
   }
 ]