[Background Fetch] Add DB corruption handler to data manager observer.

Bug: 850512
Change-Id: Iddd2773f63fd7aa0368e980a347c1bef4312f23d
Reviewed-on: https://chromium-review.googlesource.com/1128839
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574593}
13 files changed