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- Move update notification service into one module.
- Wrap up bridge as a class.
- Inject bridge and config as components into serviceImpl.
- TODO: Add test targets.
- TODO: Fix some broken due to ownership change.

Bug: 1013685
Change-Id: I1371176eb5249a048c9cc564a9056bfa747e64fb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1994177Reviewed-by: David Trainor <dtrainor@chromium.org>
Reviewed-by: Xing Liu <xingliu@chromium.org>
Commit-Queue: Hesen Zhang <hesen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#734725}