The ornamental design for a chair, as shown and described.
FIG. 1 is a front perspective view of the front, right, and top sides of a chair showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a right side view thereof, a left side view being a mirror image thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
The claimed design is indicated by the relatively dark portions in the figures. The relatively light portions within broken lines form no part of the claimed design. The broken lines following the perimeter of the relatively light portions form no part of the claimed design.