We claim the ornamental design for a comfort mat, as shown and described.
FIG. 1 is a perspective view of the comfort mat of the present invention;
FIG. 2 is a top view thereof;
FIG. 3 is a front view thereof, the rear view being a mirror image thereof;
FIG. 4 is a right side view thereof, the left side view being a mirror image thereof;
FIG. 5 is a cross-sectional view thereof taken along the line 5-5 of FIG. 2, showing a central portion of the design broken away for ease of illustration;
FIG. 6 is a bottom view thereof;
FIG. 7 is an enlarged detailed view thereof, the detail being taken in view 7 of FIG. 5; and,
FIG. 8 is an enlarged detailed view thereof, the detail being taken in view 8 of FIG. 6.