A float may be interleaved by other content, if a break is inserted
before the block-end padding/border of the float. Then there may be room
available to other content below the content-box of the float in one
fragmentainer. If the remaining part of the float (i.e. the block-end
padding/border) in the next fragmentainer is too tall for the other
content to resume there, we might not make any progress at all there. In
such cases we need to repropagate any incoming child break tokens that
we didn't get to handle and retry in a fragmentainer further ahead.

Bug: 1505182
Change-Id: I7a385ab239d3656c136b8fcd23109d1fac648de8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5063008


Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Morten Stenshorne <mstensho@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1229886}