Scrolling exhibits the same incorrect sizing issue as #1387

[rcoreilly]

Describe the bug

For the forms that were fixed by PR #1389, the scrollbar is no longer allowing you to go all the way to the bottom -- it scrolls to the same point that used to be cutoff prior to the switch from actual to alloc.

How to reproduce

in axon, layerparams

Example code

Relevant output

Platform

macOS