GitLab

Adds a OmniboxTriggeredFeatureService, accessible through
AutocompleteProviderClient, that registers features as they're triggered
which are copied to the metrics logs once an omnibox session ends.

Change-Id: I311fc20b185dd58b1acc6174321e47a38f794c67
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2437743
Commit-Queue: manuk hovanesian <manukh@chromium.org>
Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823683}