Add auto_fetch_notification_state to SavePageRequest

We need to track the state of the auto-fetch notification that's associated
with a SavePageRequest. This change adds a new field to SavePageRequest for
this purpose, updates the database schema for storing the field,
and adds access methods for setting the value through RequestCoordinator.

Bug: 883486
Change-Id: I6baa6d240efdedc210d6917870047812cba02381
Reviewed-on: https://chromium-review.googlesource.com/c/1374114
Commit-Queue: Dan H <harringtond@google.com>
Reviewed-by: Peter Williamson <petewil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#619670}
14 files changed