GitLab

- Add InternalsUIMessageHandler as observer.

- Inject Logger to TileServiceImpl.

- Inject LogSink into TileServiceScheduler and ping the observer.

- Set scheduler as LogSource.

Bug: 1066556
Change-Id: I6fdf79da6dea82327af5be1aa1b79a6cbee9926d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2264934
Commit-Queue: Hesen Zhang <hesen@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Reviewed-by: Xing Liu <xingliu@chromium.org>
Reviewed-by: Min Qin <qinmin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#786090}