merge_pr_46950

[anchor] De-function within position-try-options

Dropped 'const' from some parsing utils to make things work together.
(The parsing utils generally return non-const CSSValues).

Bug: 343516066
Change-Id: I60b881ce299eec56b54d024200673bd612a9036b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5667164
Commit-Queue: Anders Hartvoll Ruud andruud@chromium.org
Reviewed-by: Rune Lillesveen futhark@chromium.org
Cr-Commit-Position: refs/heads/main@{#1321816}