Could we hide the scheme (as we do in settings and in the omnibox)? Or hide the scheme if it's identical, e.g. both https?

I guess the scheme is always identical since we don't fill http passwords on https sites and vice versa, correct?

Correct

Dominic, do you see any security issues in hiding the http/https scheme in our dropdown items for affiliated passwords (as we already do in settings and in the omnibox)? Our UX research tells us that technical syntax in URLs can be confusing and intimidating to users.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/45a114b6068c75f3d8bff795bb13fc6169b18275

commit 45a114b6068c75f3d8bff795bb13fc6169b18275
Author: Vasilii Sukhanov <vasilii@chromium.org>
Date: Mon Aug 27 10:33:00 2018

Implement 2 rows rendering for the PSL credentials in the password dropdown.

Bug:  874029 
Change-Id: I24d337bb04becf16f8f67d1f143129ccac8624cd
Reviewed-on: https://chromium-review.googlesource.com/1186900
Commit-Queue: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: Tommy Martino <tmartino@chromium.org>
Reviewed-by: Fabio Tirelo <ftirelo@chromium.org>
Reviewed-by: Vadym Doroshenko <dvadym@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586226}
[modify] https://crrev.com/45a114b6068c75f3d8bff795bb13fc6169b18275/chrome/browser/ui/views/autofill/autofill_popup_view_native_views.cc
[modify] https://crrev.com/45a114b6068c75f3d8bff795bb13fc6169b18275/components/autofill/core/browser/suggestion.cc
[modify] https://crrev.com/45a114b6068c75f3d8bff795bb13fc6169b18275/components/autofill/core/browser/suggestion.h
[modify] https://crrev.com/45a114b6068c75f3d8bff795bb13fc6169b18275/components/password_manager/core/browser/password_autofill_manager.cc
[modify] https://crrev.com/45a114b6068c75f3d8bff795bb13fc6169b18275/components/password_manager/core/browser/password_autofill_manager_unittest.cc

I'd like to merge r586226 to M69. It's the last UI polish CL for the updated password drop-down targeted for the birthday release.
The risk is minimal because it's pure UI change.

This bug requires manual review: We are only 6 days from stable.
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), kariahda@(iOS), cindyb@(ChromeOS), govind@(Desktop)

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

How is the change looking in canary?

LGTM! See screenshots of change in Canary in #4.

The new password dropdown is behind the Finch experiment. It controls both the MD2 password and autofill dropdowns.

Approving merge to M69 branch 3497 based on comments #9, #12 and #13. Pls merge ASAP. Thank you.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/81a14b6f8e789503f786f13612ee1fa77cbb9c62

commit 81a14b6f8e789503f786f13612ee1fa77cbb9c62
Author: Vasilii Sukhanov <vasilii@chromium.org>
Date: Tue Aug 28 15:58:19 2018

Implement 2 rows rendering for the PSL credentials in the password dropdown.

TBR=tmartino@chromium.org,ftirelo@chromium.org,dvadym@chromium.org
(cherry picked from commit 45a114b6068c75f3d8bff795bb13fc6169b18275)

Bug:  874029 
Change-Id: I24d337bb04becf16f8f67d1f143129ccac8624cd
Reviewed-on: https://chromium-review.googlesource.com/1186900
Commit-Queue: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: Tommy Martino <tmartino@chromium.org>
Reviewed-by: Fabio Tirelo <ftirelo@chromium.org>
Reviewed-by: Vadym Doroshenko <dvadym@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#586226}
Reviewed-on: https://chromium-review.googlesource.com/1193845
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Cr-Commit-Position: refs/branch-heads/3497@{#826}
Cr-Branched-From: 271eaf50594eb818c9295dc78d364aea18c82ea8-refs/heads/master@{#576753}
[modify] https://crrev.com/81a14b6f8e789503f786f13612ee1fa77cbb9c62/chrome/browser/ui/views/autofill/autofill_popup_view_native_views.cc
[modify] https://crrev.com/81a14b6f8e789503f786f13612ee1fa77cbb9c62/components/autofill/core/browser/suggestion.cc
[modify] https://crrev.com/81a14b6f8e789503f786f13612ee1fa77cbb9c62/components/autofill/core/browser/suggestion.h
[modify] https://crrev.com/81a14b6f8e789503f786f13612ee1fa77cbb9c62/components/password_manager/core/browser/password_autofill_manager.cc
[modify] https://crrev.com/81a14b6f8e789503f786f13612ee1fa77cbb9c62/components/password_manager/core/browser/password_autofill_manager_unittest.cc