Door Frame

FIG. 1 is a front perspective view of a door frame showing the claimed design; FIG. 2 is a rear perspective view thereof; FIG. 3 is a left side view thereof; FIG. 4 is a front view thereof; FIG. 5 is a right side view thereof; FIG. 6 is a rear view thereof; FIG. 7 is a top view thereof; and, FIG. 8 is a bottom view thereof. The door frame includes a symbolic break along its length and width drawn in broken lines. The broken break lines and the area between the break lines forms no part of the claimed design.