Allow comments in extension config files.

chrome/common/extensions/api/chromeAuthPrivate.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": "chromeAuthPrivate",
     "nodoc": "true",
     "functions": [
       {
         "name": "setCloudPrintCredentials",
         "description": "Sets the login credentials for Cloud Print.",
         "type": "function",
         "parameters": [
@@ skipping 24 matching lines @@
                 "description": "A string result code. The value is non-empty on success only in tests.",
                 "optional": "true"
               }
             ]
           }
         ]
       }
     ]
   }
 ]