[omnibox] Connect PedalProvider to AutocompleteClientProvider

Some Pedals need to be filtered by application state regardless
of whether a query suggestion triggers the Pedal suggestion, and
to do this requires a context that can inform the Pedal system
during autocomplete time (as opposed to the later execution time).
AutocompleteClientProvider is the abstract base class for this purpose,
and works well, so it is used by this CL for the first instance
of Pedal filtering: the UpdateChrome Pedal is filtered when no
update is ready.

Bug: 893183
Change-Id: I3344b26600188c0c952ea81dba1e90a6b4133318
Reviewed-on: https://chromium-review.googlesource.com/c/1297587
Commit-Queue: Orin Jaworski <orinj@chromium.org>
Reviewed-by: Greg Thompson <grt@chromium.org>
Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606701}
15 files changed