Add tests to test the distinction between legacy name aliases and legacy shorthands.
This is a followup to the discussion in
w3c/csswg-drafts#8014 and tests the concepts
in https://drafts.csswg.org/css-cascade-5/#aliasing partly using the
rules in
https://drafts.csswg.org/css-variables/#substitution-in-shorthands .
Bug: 40834250
Change-Id: Ic8c2044a091ec609bb447c739052888a4ec6e603
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5838006
Commit-Queue: David Baron dbaron@chromium.org
Reviewed-by: Oriol Brufau obrufau@igalia.com
Cr-Commit-Position: refs/heads/main@{#1351453}