The ornamental design for an infantfurniturebase, as shown and described.
FIG. 1 is a front perspective view of the infant furniture base showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is another front perspective view thereof, but showing the infant furniture base in use as a bassinet, with legs, bassinet mattress support, and camera with lighting shown in broken lines; and,
FIG. 9 is another front perspective view thereof, but showing the infant furniture base in use as an infant sofa, with legs, seating element, and camera with lighting shown in broken lines.
The broken lines depict portions of the infant furniture base that form no part of the claimed design.