[layout] Rework replaced %-size.

Previously we needed to set both the replaced and non-replaced
%-resolution size on the constraint space.

Strictly speaking we don't need both (most of the time), and only
really need to communicate the replace %-size to inline layout so that
it can resolve replaced children correctly.

Change-Id: I0efe82849a56d20744cc769d9889b276f00e8260
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6337084
Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Commit-Queue: Ian Kilpatrick <ikilpatrick@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1431206}