GitLab

There's a bunch of stuff here to support non-Content processes like a
standalone Service Manager and Content-free service processes. None of
it is used in production anymore (since the end of mus+ash), so this CL
deletes all of it.

Bug: 977637
Change-Id: I93c9a54ccf39e5659d0aae2f495bc1c378ae5c4c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2410919Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Ken Rockot <rockot@google.com>
Cr-Commit-Position: refs/heads/master@{#806854}