Allow comments in extension config files.

chrome/common/extensions/api/test.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": "test",
     "nodoc": true,
     "types": [],
     "functions": [
       {
         "name": "getConfig",
         "type": "function",
         "description": "Gives configuration options set by the test.",
@@ skipping 97 matching lines @@
             "properties": {
               "data": { "type": "string", "description": "Additional information." },
               "lastMessage": { "type": "boolean", "description": "True if this was the last message for this test" }
             }
           }
         ]
       }
     ]
   }
 ]