A upper left corner non-focusable object don't have chance to show in viewport
when scroller which have content without viewport get focus first because it
always auto-scroll to focusable content when scroller get focus.
If a user set focus to scroller to control scroll bar and want to see upper left
corner non-focusale object(e.g. label) first, there is no way.
See, elementary_test -to focus4. if there is label at upper left corner, you
always have to move scroll bar to read the label.
This also fixes T7274