How about min width?

Min-width should be defined by the primary (left) and secondary (right) text labels: both should never be truncated. Otherwise match the field width until the max-width (480dp) is reached.

What's the reason to have max width? For the generated password suggestion the content should never be truncated. Is your concern about editing state and the user typing many characters to the field?

The max-width is to prevent states like this where the input field is very wide:

Deleted: No Max-Width.png 57.4 KB

	No Max-Width.png 57.4 KB View Download

LGTM, thanks!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/184d5957347e7c56567f8bad00590e36e741604d

commit 184d5957347e7c56567f8bad00590e36e741604d
Author: Vasilii Sukhanov <vasilii@chromium.org>
Date: Thu Aug 30 15:21:42 2018

Limit the width of the password generation drop-down to 480dp.

This is to prevent the popup from growing on very long password fields.

TBR=rouslan@chromium.org

Bug:  873121 
Change-Id: Ia45a59003405181f968897d2d333969b20c3f127
Reviewed-on: https://chromium-review.googlesource.com/1194010
Commit-Queue: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: Fabio Tirelo <ftirelo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587586}
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/android/autofill/password_generation_popup_view_android.cc
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/android/autofill/password_generation_popup_view_android.h
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/autofill/autofill_popup_controller_impl.cc
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/autofill/autofill_popup_controller_impl.h
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/autofill/autofill_popup_layout_model_unittest.cc
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/autofill/autofill_popup_view_delegate.h
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/cocoa/touchbar/credit_card_autofill_touch_bar_controller_unittest.mm
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/passwords/password_generation_popup_controller.h
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/passwords/password_generation_popup_controller_impl.cc
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/passwords/password_generation_popup_controller_impl.h
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/passwords/password_generation_popup_view.h
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/passwords/password_generation_popup_view_browsertest.cc
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/views/autofill/autofill_popup_base_view.cc
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/views/autofill/autofill_popup_base_view.h
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/views/autofill/autofill_popup_base_view_browsertest.cc
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/views/autofill/autofill_popup_view_native_views.cc
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/views/autofill/autofill_popup_view_native_views_unittest.cc
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/views/autofill/autofill_popup_view_views_browsertest.cc
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/views/passwords/password_generation_popup_view_views.cc
[modify] https://crrev.com/184d5957347e7c56567f8bad00590e36e741604d/chrome/browser/ui/views/passwords/password_generation_popup_view_views.h