Rewrite base::JSONReader to be 35-40% faster, depending on the input string.

base/base.gypi

 # 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.
 
 {
   'target_defaults': {
     'variables': {
       'base_target': 0,
     },
     'target_conditions': [
@@ skipping 123 matching lines @@
           'files/file_path_watcher_win.cc',
           'float_util.h',
           'format_macros.h',
           'global_descriptors_posix.cc',
           'global_descriptors_posix.h',
           'gtest_prod_util.h',
           'hash_tables.h',
           'id_map.h',
           'json/json_file_value_serializer.cc',
           'json/json_file_value_serializer.h',
+          'json/json_parser.cc',
+          'json/json_parser.h',
           'json/json_reader.cc',
           'json/json_reader.h',
           'json/json_string_value_serializer.cc',
           'json/json_string_value_serializer.h',
           'json/json_value_converter.h',
           'json/json_writer.cc',
           'json/json_writer.h',
           'json/string_escape.cc',
           'json/string_escape.h',
           'lazy_instance.cc',
@@ skipping 774 matching lines @@
             'third_party/xdg_mime/xdgmimemagic.c',
             'third_party/xdg_mime/xdgmimemagic.h',
             'third_party/xdg_mime/xdgmimeparent.c',
             'third_party/xdg_mime/xdgmimeparent.h',
           ],
         },
       ],
     }],
   ],
 }