Remove reference to base/memory/ref_counted.cc from GN bootstrap.

tools/gn/bootstrap/bootstrap.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 # This file isn't officially supported by the Chromium project. It's maintained
 # on a best-effort basis by volunteers, so some things may be broken from time
 # to time. If you encounter errors, it's most often due to files in base that
 # have been added or moved since somebody last tried this script. Generally
 # such errors are easy to diagnose.
@@ skipping 379 matching lines @@
       'base/hash.cc',
       'base/json/json_parser.cc',
       'base/json/json_reader.cc',
       'base/json/json_string_value_serializer.cc',
       'base/json/json_writer.cc',
       'base/json/string_escape.cc',
       'base/lazy_instance.cc',
       'base/location.cc',
       'base/logging.cc',
       'base/md5.cc',
-      'base/memory/ref_counted.cc',
       'base/memory/ref_counted_memory.cc',
       'base/memory/singleton.cc',
       'base/memory/weak_ptr.cc',
       'base/message_loop/incoming_task_queue.cc',
       'base/message_loop/message_loop.cc',
       'base/message_loop/message_loop_task_runner.cc',
       'base/message_loop/message_pump.cc',
       'base/message_loop/message_pump_default.cc',
       'base/metrics/bucket_ranges.cc',
       'base/metrics/histogram.cc',
@@ skipping 330 matching lines @@
     cmd.append('-v')
   cmd.append('gn')
   check_call(cmd)
 
   if not options.debug and not is_win:
     check_call(['strip', os.path.join(build_dir, 'gn')])
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))