Don't consume into block in css_parsing_utils::ConsumeSteps
Fixes crash for e.g. steps(2, ()).
Bug: 40941162
Change-Id: I50eeb55cb7b8c837082ad620ba3b732026cf641c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5860080
Reviewed-by: Steinar H Gunderson sesse@chromium.org
Commit-Queue: Anders Hartvoll Ruud andruud@chromium.org
Cr-Commit-Position: refs/heads/main@{#1355443}