[css-pseudo] Unify the default styles for ::marker

This patch avoids triplicating the default styles for the ::marker
pseudo-element in StyleResolver, LayoutListMarker and LayoutNGListItem.
Now they will only be in StyleResolver.

When no style has been specified for ::marker, using StyleResolver has
some overhead that reduces the the flexbox_with_list_item.html perf test
by 2%-5%. But unifying the code for ::marker styles seems worth it,
since it will be necessary to avoid some inconsistences like the
propagation of text decorations.


Change-Id: I9b30d43321f8076873256e20f97779bc279ec940
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1971929
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Commit-Queue: Oriol Brufau <obrufau@igalia.com>
Cr-Commit-Position: refs/heads/master@{#725913}
5 files changed