Fix 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 355 matching lines @@
       'base/third_party/superfasthash/superfasthash.c',
   ])
   static_libraries['base']['sources'].extend([
       'base/allocator/allocator_check.cc',
       'base/allocator/allocator_extension.cc',
       'base/at_exit.cc',
       'base/base_paths.cc',
       'base/base_switches.cc',
       'base/callback_internal.cc',
       'base/command_line.cc',
+      'base/debug/activity_tracker.cc',
       'base/debug/alias.cc',
       'base/debug/stack_trace.cc',
       'base/debug/task_annotator.cc',
       'base/environment.cc',
       'base/files/file.cc',
       'base/files/file_enumerator.cc',
       'base/files/file_path.cc',
       'base/files/file_path_constants.cc',
       'base/files/file_tracing.cc',
       'base/files/file_util.cc',
@@ skipping 339 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:]))