common.mk: update from platform2

  - 102a6341dde2881fe913563cb4fab995153958b6 common-mk: common.mk: add note about copybara automation by Mike Frysinger <vapier@chromium.org>

GitOrigin-RevId: 102a6341dde2881fe913563cb4fab995153958b6
Change-Id: I9ddf1ff66bc5c9bb9c83412ad72c9c8af51c593f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/microbenchmarks/+/6474871
Auto-Submit: Copybara Service <copybara-worker-blackhole@google.com>
Bot-Commit: Copybara Service <copybara-worker-blackhole@google.com>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Copybara Service <copybara-worker-blackhole@google.com>
diff --git a/common.mk b/common.mk
index 03e886c..dfaa8ca 100644
--- a/common.mk
+++ b/common.mk
@@ -9,6 +9,10 @@
 #  The authoritative common.mk is located in:
 #    https://chromium.googlesource.com/chromiumos/platform2/+/HEAD/common-mk
 #  Please make all changes there, then copy into place in other repos.
+#
+#  The copybara service is used to automatically sync updates for projects
+#  hosted on Chromium GoB hosts.  Please see:
+#  //google3/third_party/copybara-gsubtreed/chromiumos_platform2/copy.bara.sky
 # NOTE NOTE NOTE
 #
 # This file provides a common architecture for building C/C++ source trees.