Fix a CHECK-failure on invalid :nth-last-child().
In non-debug builds, we'd get out of sync and most likely
ignore the rest of the stylesheet.
Fixed: 355451192
Change-Id: I27f03a0de4624403f74e45b8c5bb70cd0a80950c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5759706
Reviewed-by: Rune Lillesveen futhark@chromium.org
Auto-Submit: Steinar H Gunderson sesse@chromium.org
Commit-Queue: Rune Lillesveen futhark@chromium.org
Commit-Queue: Steinar H Gunderson sesse@chromium.org
Cr-Commit-Position: refs/heads/main@{#1337276}