memory-infra: Start disentangling tracing from memory-infra

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 506 matching lines @@
       'base/trace_event/heap_profiler_type_name_deduplicator.cc',
       'base/trace_event/memory_allocator_dump.cc',
       'base/trace_event/memory_allocator_dump_guid.cc',
       'base/trace_event/memory_dump_manager.cc',
       'base/trace_event/memory_dump_provider_info.cc',
       'base/trace_event/memory_dump_request_args.cc',
       'base/trace_event/memory_dump_scheduler.cc',
       'base/trace_event/memory_dump_session_state.cc',
       'base/trace_event/memory_infra_background_whitelist.cc',
       'base/trace_event/memory_peak_detector.cc',
+      'base/trace_event/memory_tracing_observer.cc',
       'base/trace_event/process_memory_dump.cc',
       'base/trace_event/process_memory_maps.cc',
       'base/trace_event/process_memory_totals.cc',
       'base/trace_event/trace_buffer.cc',
       'base/trace_event/trace_config.cc',
       'base/trace_event/trace_config_category_filter.cc',
       'base/trace_event/trace_event_argument.cc',
       'base/trace_event/trace_event_filter.cc',
       'base/trace_event/trace_event_impl.cc',
       'base/trace_event/trace_event_memory_overhead.cc',
@@ skipping 242 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:]))