I'm well aware of the class hierarchy ;)

Key points:
1. CGUITextLayout::UpdateScrollInfo already returns a bool appropriately.
2. CGUILabel::Process might in future do other things other than update the scroll info, so let's not make assumptions outside the class.
3. Simple fix here is returning the bool appropriately from CGUILabel::Process.  Advantage being you'll fix it for all the other controls you list at the same time, right?