Fix crash when parsing calc() within steps().
Bug: 40946458
Change-Id: I8c5c73a58b89ba6b6741450222a7bd426297aec2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6062257
Auto-Submit: Steinar H Gunderson sesse@chromium.org
Commit-Queue: Steinar H Gunderson sesse@chromium.org
Commit-Queue: Rune Lillesveen futhark@chromium.org
Reviewed-by: Rune Lillesveen futhark@chromium.org
Cr-Commit-Position: refs/heads/main@{#1390238}