Resolve viewport units in @page against default page box size.
For document contents for pagination we use the page area size of the
first page, which is defined as the initial containing block, when
resolving viewport units. This won't do for viewport units inside @page
(and page margin boxes), because then there would be circular
dependencies, as the size property may very well use viewport units,
and the page area size may be derived from size.
Make sure that we use the default page box size (from print parameters
(typically based on settings in the print preview UI)) when resolving
viewport units inside @page.
Bug: 380860850
Change-Id: I4c1f3d30c8aa5a678ed2a1ad414279916d28c969
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6049104
Commit-Queue: Morten Stenshorne mstensho@chromium.org
Reviewed-by: Rune Lillesveen futhark@chromium.org
Cr-Commit-Position: refs/heads/main@{#1388330}