The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/57eea4eb4ecb1176107e7a2c3a8674b5f9de4c59

commit 57eea4eb4ecb1176107e7a2c3a8674b5f9de4c59
Author: Sebastien Lalancette <seblalancette@chromium.org>
Date: Wed Dec 19 13:37:08 2018

Fixed arrow-down selecting first Autocomplete entry.

A fix was made a while ago to allow auto-selecting the first Autofill entry
on arrow-down when a user was on an input box that had Autofill suggestions,
but the pop-up would be hidden. This wasn't working on Autocomplete, since
we were not keeping track of the value of |autoselect_first_suggestion|.

Added the value to the QueryHandler, and passing it back to the
SuggestionsHandler when responding with the found suggestions.

Added unit tests and tested manually in Chromium.

Bug:  912271 
Change-Id: Ic9dc3c7927755b0b0939c8812f808ac7522f79fb
Reviewed-on: https://chromium-review.googlesource.com/c/1378488
Reviewed-by: Sebastien Seguin-Gagnon <sebsg@chromium.org>
Commit-Queue: Sebastien Lalancette <seblalancette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#617815}
[modify] https://crrev.com/57eea4eb4ecb1176107e7a2c3a8674b5f9de4c59/components/autofill/core/browser/autocomplete_history_manager.cc
[modify] https://crrev.com/57eea4eb4ecb1176107e7a2c3a8674b5f9de4c59/components/autofill/core/browser/autocomplete_history_manager.h
[modify] https://crrev.com/57eea4eb4ecb1176107e7a2c3a8674b5f9de4c59/components/autofill/core/browser/autocomplete_history_manager_unittest.cc
[modify] https://crrev.com/57eea4eb4ecb1176107e7a2c3a8674b5f9de4c59/components/autofill/core/browser/autofill_manager.cc
[modify] https://crrev.com/57eea4eb4ecb1176107e7a2c3a8674b5f9de4c59/components/autofill/core/browser/autofill_manager.h
[modify] https://crrev.com/57eea4eb4ecb1176107e7a2c3a8674b5f9de4c59/components/autofill/core/browser/autofill_manager_unittest.cc
[modify] https://crrev.com/57eea4eb4ecb1176107e7a2c3a8674b5f9de4c59/components/autofill/core/browser/mock_autocomplete_history_manager.h