GitLab

- Better explain ownership semantics.
- DCHECK the code runs on the UI thread.
- Use base::TimeDelta in more places.
- Pass non-POD objects by const-reference.
- Add an OWNERS file.
- Fix nits.

Change-Id: Iaa41d368882c08a56977ee418416c31e2bdc46dc
Reviewed-on: https://chromium-review.googlesource.com/c/1496538Reviewed-by: Malay Keshav <malaykeshav@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636900}