Declare component Services>Sync in various OWNERS files

This allows various tools like the flakiness dashboard associate flakes
to the appropriate component.

Most importantly, this allows better monitoring of flakes for the main
source of test flakiness: integration tests under chrome/browser/sync.

Bug: 953364
Change-Id: I5c14daa38b93f20611f816dd2c58a51c122e1fe8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1571657
Auto-Submit: Mikel Astiz <mastiz@chromium.org>
Commit-Queue: Marc Treib <treib@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652110}
7 files changed