Separate out source sets for src/chromeos subdirs

Its good to break huge packages into smaller packages,
especially if they are already separate directories.

This breaks a number of packages out of the chromeos monolith package,
starting with chromeos/settings, and then any other packages that are
necessary for the chromeos/settings package to be separated.

Bug: 446937
Change-Id: I71909b7e7afa79f4f26d1dbac5217a3f4c769b5b
Reviewed-on: https://chromium-review.googlesource.com/c/1268315
Commit-Queue: A Olsen <olsen@chromium.org>
Reviewed-by: Ryo Hashimoto <hashimoto@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
Cr-Commit-Position: refs/heads/master@{#598302}
5 files changed