Allow writing-mode property in @page.
There are valid use cases for this inside @page margins, so it makes
sense to allow it for @page as well.
Bug: 40286153
Change-Id: If3433ec4b07d05e4335450e8e22ea43383da455a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5587745
Reviewed-by: Ian Kilpatrick ikilpatrick@chromium.org
Commit-Queue: Morten Stenshorne mstensho@chromium.org
Cr-Commit-Position: refs/heads/main@{#1309524}