Container content persists after dragging parent down

[Korysam15]

Steps to Reproduce:

1. Launch the example application
2. Select standard
3. Click Load Layout
4. Click and drag to resize the Acme.inc tab all the way down to the bottom of the screen and release
5. The container is now gone, but the contents of the Acme.inc tab are still at the same position

NOTE: If you then click and drag the container up, the Acme.inc content will then re-position itself properly. This ONLY happens when a user clicks and drags the container down to the bottom of the screen.

It seems to me that the containers virtualRectingRequiredEvent() is not firing off and should be. I tried to do some digging into this but was unable to find the fix.

Expected behavior:

I would expect that when a user performs these actions that the contents of the container should move with the container itself and not be visible as the container itself is not visible.