As first reported in crbug.com/799014#c15

Root cause, I think, is that LayoutView::UpdateAfterLayout calls into TextAutosizer::UpdatePageInfo during the lifespan of the top-level TextAutosizer::LayoutScope.

Maybe we should early-return from UpdatePageInfo if we're in the middle of a printing layout?

This bug will probably sit for a while, since our resident TextAutosizer expert is out on leave.