Per a11y policy, this is must-fix for M66.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4e2726bb8e7ce559883691f159403128486883f3

commit 4e2726bb8e7ce559883691f159403128486883f3
Author: Alexander Alekseev <alemate@chromium.org>
Date: Wed Mar 07 05:33:23 2018

Chrome OS OOBE: a11y: announce "Advanced Option" screen onload

This Cl makes "Advanced options" screen accessible.

Bug:  805489 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Id59ee85ed6378137b4c660fcc81df49194c3312b
Reviewed-on: https://chromium-review.googlesource.com/952776
Reviewed-by: Wenzhao (Colin) Zang <wzang@chromium.org>
Commit-Queue: Alexander Alekseev <alemate@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541359}
[modify] https://crrev.com/4e2726bb8e7ce559883691f159403128486883f3/chrome/app/chromeos_strings.grdp
[modify] https://crrev.com/4e2726bb8e7ce559883691f159403128486883f3/chrome/browser/resources/chromeos/login/oobe_welcome.html
[modify] https://crrev.com/4e2726bb8e7ce559883691f159403128486883f3/chrome/browser/ui/webui/chromeos/login/network_screen_handler.cc
[modify] https://crrev.com/4e2726bb8e7ce559883691f159403128486883f3/ui/login/display_manager.js

Requesting merge. There is a change to .grdp , but it only removes a string.

This bug requires manual review: There is .grd file changes and we are only 39 days from stable.
Please contact the milestone owner if you have questions.
Owners: cmasso@(Android), cmasso@(iOS), josafat@(ChromeOS), abdulsyed@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0a9ee86cc69795bd8e218d732bc5bbc7dc5d11aa

commit 0a9ee86cc69795bd8e218d732bc5bbc7dc5d11aa
Author: Alexander Alekseev <alemate@chromium.org>
Date: Tue Mar 13 22:39:45 2018

Chrome OS OOBE: a11y: announce "Advanced Option" screen onload

This Cl makes "Advanced options" screen accessible.

TBR=alemate@chromium.org

(cherry picked from commit 4e2726bb8e7ce559883691f159403128486883f3)

Bug:  805489 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Id59ee85ed6378137b4c660fcc81df49194c3312b
Reviewed-on: https://chromium-review.googlesource.com/952776
Reviewed-by: Wenzhao (Colin) Zang <wzang@chromium.org>
Commit-Queue: Alexander Alekseev <alemate@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#541359}
Reviewed-on: https://chromium-review.googlesource.com/961499
Reviewed-by: Alexander Alekseev <alemate@chromium.org>
Cr-Commit-Position: refs/branch-heads/3359@{#217}
Cr-Branched-From: 66afc5e5d10127546cc4b98b9117aff588b5e66b-refs/heads/master@{#540276}
[modify] https://crrev.com/0a9ee86cc69795bd8e218d732bc5bbc7dc5d11aa/chrome/app/chromeos_strings.grdp
[modify] https://crrev.com/0a9ee86cc69795bd8e218d732bc5bbc7dc5d11aa/chrome/browser/resources/chromeos/login/oobe_welcome.html
[modify] https://crrev.com/0a9ee86cc69795bd8e218d732bc5bbc7dc5d11aa/chrome/browser/ui/webui/chromeos/login/network_screen_handler.cc
[modify] https://crrev.com/0a9ee86cc69795bd8e218d732bc5bbc7dc5d11aa/ui/login/display_manager.js