Allow comments in extension config files.

chrome/common/extensions/api/experimental.infobars.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.infobars",
     "dependencies": [ "windows" ],
     "types": [],
     "functions": [
       {
         "name": "show",
         "type": "function",
         "description": "Shows an infobar in the specified tab. The infobar will be closed automatically when the tab navigates. Use window.close() to close the infobar before then.",
@@ skipping 27 matching lines @@
               {
                 "name": "window", "$ref": "Window", "description": "Contains details about the window in which the infobar was created."
               }
             ]
           }
         ]
       }
     ]
   }
 ]