Allow trailing comma in JSON policy files.

base/base.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'includes': [
     '../build/win_precompile.gypi',
@@ skipping 132 matching lines @@
         'i18n/break_iterator_unittest.cc',
         'i18n/char_iterator_unittest.cc',
         'i18n/case_conversion_unittest.cc',
         'i18n/file_util_icu_unittest.cc',
         'i18n/icu_string_conversions_unittest.cc',
         'i18n/number_formatting_unittest.cc',
         'i18n/rtl_unittest.cc',
         'i18n/string_search_unittest.cc',
         'i18n/time_formatting_unittest.cc',
         'json/json_reader_unittest.cc',
+        'json/json_value_serializer_unittest.cc',
         'json/json_writer_unittest.cc',
         'json/string_escape_unittest.cc',
         'lazy_instance_unittest.cc',
         'linked_list_unittest.cc',
         'logging_unittest.cc',
         'mac/foundation_util_unittest.mm',
         'mac/mac_util_unittest.mm',
         'mac/objc_property_releaser_unittest.mm',
         'md5_unittest.cc',
         'memory/linked_ptr_unittest.cc',
@@ skipping 282 matching lines @@
           'msvs_settings': {
             'VCLinkerTool': {
               'SubSystem': '2',         # Set /SUBSYSTEM:WINDOWS
             },
           },
         },
       ],
     }],
   ],
 }