[LayoutNG] Remove OverflowSize from box fragments for now.

... in favour of IntrinsicBlockSize(). We weren't using inline overflow
size, and "overflow" was incorrect for how it was being used.

This also moves it to the layout result.

Bug: 635619
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_layout_ng
Change-Id: Idd6c63dd5e0712c69f81bed21a03ad2be4c9331a
Reviewed-on: https://chromium-review.googlesource.com/701357
Commit-Queue: Ian Kilpatrick <ikilpatrick@chromium.org>
Reviewed-by: Morten Stenshorne <mstensho@opera.com>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#506799}
17 files changed