commit 7268747ad6023df3c4ff90070213b293fba53469
author Evelynn Kaplan <evelynn.kaplan@microsoft.com> Wed May 01 18:30:44 2024
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Wed May 01 18:30:44 2024
tree bd330e23644a44548df9e62427051ed04a94d71d
parent 69dab6beefd12b45ea1c78e90a08bc7243cbdd9c

Respect hidden scrollbar styling when user prefers default scrollbars

A previous series of CLs implemented logic that could allow users to
disable custom scrollbar styling based on a web preference:
CL:5194932
CL:5262985

This CL adds a change that will still allow scrollbars to be styled via
`::-webkit-scrollbar: { display: none }` and `scrollbar-width: none`,
allowing web authors to still hide scrollbars using these styles.

The input control also uses `::-webkit-scrollbar: { display: none }` in
its native styling, so this change fixes a bug where empty scrollbars
were being added to inputs. To protect against regressions,
'fast/forms' has been added to the virtual test suite run with this
web setting enabled.

This CL also adds ComputedStyle::UsedScrollbarWidth()
and ComputedStyle::UsedScrollbarColor() functions that should be used
in favor of the standard versions of these functions so that
styles are calculated correctly based on the user preference. This is
done in place of doing the adjustment in StyleAdjuster (added in
CL:5262985) to ensure that the ComputedStyle itself remains untouched
by the user setting.

Bug: 1012117
Change-Id: I92f141e6fdc180a600969aa7c2f6fc8675b07bb4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5373402
Reviewed-by: Alison Maher <almaher@microsoft.com>
Commit-Queue: Evelynn Kaplan <evelynn.kaplan@microsoft.com>
Reviewed-by: Mason Freed <masonf@chromium.org>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1294974}