Allow trailing comma in JSON policy files.

base/json/json_value_serializer.h

 // 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.
 
 #ifndef BASE_JSON_JSON_VALUE_SERIALIZER_H_
 #define BASE_JSON_JSON_VALUE_SERIALIZER_H_
 #pragma once
 
 #include <string>
 
@@ skipping 56 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(JSONStringValueSerializer);
 };
 
 class BASE_EXPORT JSONFileValueSerializer : public base::ValueSerializer {
  public:
   // json_file_patch is the path of a file that will be source of the
   // deserialization or the destination of the serialization.
   // When deserializing, the file should exist, but when serializing, the
   // serializer will attempt to create the file at the specified location.
   explicit JSONFileValueSerializer(const FilePath& json_file_path)
-    : json_file_path_(json_file_path) {}
+    : json_file_path_(json_file_path),
+      allow_trailing_comma_(false) {}
 
   virtual ~JSONFileValueSerializer() {}
 
   // DO NOT USE except in unit tests to verify the file was written properly.
   // We should never serialize directly to a file since this will block the
   // thread. Instead, serialize to a string and write to the file you want on
   // the file thread.
   //
   // Attempt to serialize the data structure represented by Value into
   // JSON.  If the return value is true, the result will have been written
@@ skipping 21 matching lines @@
   // File-specific error messages that can be returned.
   static const char* kAccessDenied;
   static const char* kCannotReadFile;
   static const char* kFileLocked;
   static const char* kNoSuchFile;
 
   // Convert an error code into an error message.  |error_code| is assumed to
   // be a JsonFileError.
   static const char* GetErrorMessageForCode(int error_code);
 
+  void set_allow_trailing_comma(bool new_value) {
+    allow_trailing_comma_ = new_value;
+  }
+
  private:
   FilePath json_file_path_;
+  bool allow_trailing_comma_;
 
   // A wrapper for file_util::ReadFileToString which returns a non-zero
   // JsonFileError if there were file errors.
   int ReadFileToString(std::string* json_string);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSONFileValueSerializer);
 };
 
 #endif  // BASE_JSON_JSON_VALUE_SERIALIZER_H_