Reclaiming

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/331a3ec24339b1d06ba82fd9e3ca0f07b49ddd8e

commit 331a3ec24339b1d06ba82fd9e3ca0f07b49ddd8e
Author: Christopher Grant <cjgrant@chromium.org>
Date: Tue Jan 09 23:14:28 2018

VR: Preserve omnibox text through a failed voice search attempt

When voice input is triggered via omnibox, an unsuccessful voice search should
land the user back at the omnibox with any previously typed text still present.
This change moves the omnibox-clearing action from "when the omnibox changes
visibility" to "when the omnibox is in the mode stack".  This way, even when
omnibox is hidden by voice input, it's still considered to be active, and the
field isn't cleared.

Similarly, also leave the autocomplete controller running if we enter
voice mode, rather than restarting it when we leave voice mode.

BUG= 799244 
R=ymalik

Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: If29729867ad0810be92f9b7b089cfeab17cf1f12
Reviewed-on: https://chromium-review.googlesource.com/857543
Reviewed-by: Yash Malik <ymalik@chromium.org>
Commit-Queue: Christopher Grant <cjgrant@chromium.org>
Cr-Commit-Position: refs/heads/master@{#528158}
[modify] https://crrev.com/331a3ec24339b1d06ba82fd9e3ca0f07b49ddd8e/chrome/browser/vr/model/model.cc
[modify] https://crrev.com/331a3ec24339b1d06ba82fd9e3ca0f07b49ddd8e/chrome/browser/vr/model/model.h
[modify] https://crrev.com/331a3ec24339b1d06ba82fd9e3ca0f07b49ddd8e/chrome/browser/vr/ui_scene_creator.cc

Fix verified in M66 Canary build.
Covered by testcase "Exit Voice input by clicking close button or controller app button returns back to text entry mode." in the "VR Browsing: Omnibox text entry manual test plan"