GitLab

Adds logic to switch between LayoutFlexibleBox and
LayoutDeprecatedFlexibleBox when clamping changes.

This is necessary as LayoutDeprecatedFlexibleBox is the only
place that currently provides support for clamping.

BUG=993813
TEST=none

Change-Id: I88dc4ce0195faf08870afeb9e8e5fce338a29476
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1754922
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#688209}