Allow comments in extension config files.

chrome/common/extensions/api/pageAction.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": "pageAction",
     "dependencies": [ "tabs" ],
     "types": [],
     "functions": [
       {
         "name": "show",
         "type": "function",
         "description": "Shows the page action. The page action is shown whenever the tab is selected.",
@@ skipping 83 matching lines @@
         "parameters": [
           {
             "name": "tab",
             "$ref": "Tab"
           }
         ]
       }
     ]
   }
 ]