commit 6fc4cbe9e6fd83095e43125a3f407f7bc4874115
author Oriol Brufau <obrufau@igalia.com> Wed Feb 05 14:54:23 2020
committer Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> Wed Feb 05 15:09:06 2020
tree 124c635df39537b3301ded4265ec0c9e7a573798
parent e92baffe525abd5eddb6fb8b7b9aa6f6b10952d8

[css-pseudo] Fix legacy ::marker margins not getting updated

Outside markers behave out-of-flowish, so their intrinsic contribution
to the list item should be 0.

In legacy, this is done by adding negative margins, so that the width of
the marker plus its margins are 0.

However, when calculating the intrinsic contributions of the children,
the code uses the margins in the computed style, not the margins of the
box. Therefore, the marker code used to replace the computed style with
another one that had the changed margins.

This approach was error-prone, for example special care was needed to
reapply the previously calculated margins when the computed style
changed, in order to avoid triggering unnecessary layout.

However, this caused a problem: if 'list-style-position' changed, the
old margins were preserved. But the margins depend on whether the marker
is inside or outside!

This patch fixes the problem and stops changing the computed style of
the marker.

For inside markers, margins don't depend on the size of the marker, and
they were already applied to the computed style in style_adjuster.cc, so
they work well. For outside markers, the patch skips them when
calculating the intrinsic size of the list item.

Bug: 1048672, 457718

TEST=external/wpt/css/css-pseudo/marker-intrinsic-contribution-001.html
TEST=external/wpt/css/css-pseudo/marker-intrinsic-contribution-002.html

The former test fails in LayoutNG because trailing marker spaces are not
preserved, and fails in legacy due to the lack of 'content' support.

Change-Id: Ic21603e9fe1b17b11237286dac3f207b1837a07e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2035962
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Commit-Queue: Oriol Brufau <obrufau@igalia.com>
Cr-Commit-Position: refs/heads/master@{#738550}