Update GN bootstrap file list.

This updates the GN bootstrap build to reflect recent changes in //base:
  - //base/files/file_descriptor_watcher_posix.cc was added
  - //base/memory/ref_counted was re-added
  - //base/trace_event/winheap_dump_provider_win.cc was removed.

R=brettw@chromium.org

Review-Url: https://codereview.chromium.org/2374873002
Cr-Original-Commit-Position: refs/heads/master@{#421381}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: fec688caede93a05edadb944246d5a46f94ec615
diff --git a/tools/gn/bootstrap/bootstrap.py b/tools/gn/bootstrap/bootstrap.py
index e830454..b6a113d 100755
--- a/tools/gn/bootstrap/bootstrap.py
+++ b/tools/gn/bootstrap/bootstrap.py
@@ -379,6 +379,7 @@
       'base/debug/task_annotator.cc',
       'base/environment.cc',
       'base/files/file.cc',
+      'base/files/file_descriptor_watcher_posix.cc',
       'base/files/file_enumerator.cc',
       'base/files/file_path.cc',
       'base/files/file_path_constants.cc',
@@ -397,6 +398,7 @@
       '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',
@@ -685,7 +687,6 @@
         'base/timer/hi_res_timer_manager_win.cc',
         'base/trace_event/heap_profiler_allocation_register_win.cc',
         'base/trace_event/trace_event_etw_export_win.cc',
-        'base/trace_event/winheap_dump_provider_win.cc',
         'base/win/enum_variant.cc',
         'base/win/event_trace_controller.cc',
         'base/win/event_trace_provider.cc',