Revert "Remove the use of overrideLogicalContentHeight from the regions' processing model. This prevents flexbox containers from overriding the height value computed when flowing content into auto-height regions."

This reverts https://src.chromium.org/viewvc/blink?view=revision&revision=154928
It caused crashes in fast/regions/flow-region-into-itself-crash.html.

BUG=256233
TBR=badea@adobe.com,jchaffraix@chromium.org

Review URL: https://codereview.chromium.org/20472002

git-svn-id: svn://svn.chromium.org/blink/trunk@154934 bbb929c8-8fbe-4397-9dbb-9b2b20218538