Talked to Robbie, it seems we can use gatekeeer for this. I started https://chromium-review.googlesource.com/437614

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/build/+/293d7af1e3024eb5cfcc528159802d8837d329be

commit 293d7af1e3024eb5cfcc528159802d8837d329be
Author: Roberto Carrillo <robertocn@google.com>
Date: Tue Feb 21 19:54:57 2017

Add the component mapping updater bot to gatekeeper.

The bot periodically runs a script that traverses src/
and examines OWNERS files and extracts the `# TEAM:` 
and `# COMPONENT:` tags in those files into a mapping
that is then uploaded (if modified) to:
https://storage.googleapis.com/chromium-owners/component_map.json.

We are doing this on a tryserver because that's where we had the
capacity. After some time, we expect to move it to a more
approriate location.

BUG= 688579 
R=​martiniss

Change-Id: Ifd51c008fabb1f94646894c942e5e5a04b95b8cd
Reviewed-on: https://chromium-review.googlesource.com/437614
Commit-Queue: Roberto Carrillo <robertocn@chromium.org>
Reviewed-by: Stephen Martinis <martiniss@chromium.org>

[modify] https://crrev.com/293d7af1e3024eb5cfcc528159802d8837d329be/scripts/slave/gatekeeper.json

This is fixed, but not that to verify, we need a failure in https://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_component_updater to happen, and confirm that chromium-component-mapping@google.com is notified.