Allow trailing comma in JSON policy files.

base/json/json_value_serializer.cc

 // Copyright (c) 2011 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.
 
 #include "base/json/json_value_serializer.h"
 
 #include "base/file_util.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/string_util.h"
@@ skipping 86 matching lines @@
   int error = ReadFileToString(&json_string);
   if (error != JSON_NO_ERROR) {
     if (error_code)
       *error_code = error;
     if (error_str)
       *error_str = GetErrorMessageForCode(error);
     return NULL;
   }
 
   JSONStringValueSerializer serializer(json_string);
+  serializer.set_allow_trailing_comma(allow_trailing_comma_);
   return serializer.Deserialize(error_code, error_str);
 }