Load external @page margin box resources.
First of all, trigger loading when computing @page margin box style,
just like we already do for @page properties in StyleForPage().
Secondly, attempt to make sure that the resources actually have loaded
before entering print mode. This was already working for @page
properties, and for regular document contents, but not for @page margin
boxes styles. Move the logic into StyleResolver, rather than keeping it
in Document::InitiateStyleOrLayoutDependentLoadForPrint().
Bug: 40341678, 341947679
Change-Id: I553d1c358614b460710975d47e6edd0f4e8f90d0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5649256
Reviewed-by: Rune Lillesveen futhark@chromium.org
Commit-Queue: Morten Stenshorne mstensho@chromium.org
Reviewed-by: Traian Captan tcaptan@chromium.org
Cr-Commit-Position: refs/heads/main@{#1319694}