The ornamental design for a chair, as shown and described.
FIG. 1 is a front elevational view of the chair comprising my new design;
FIG. 2 is a top view thereof;
FIG. 3 is a side elevational view thereof, the opposite elevational view
being a mirror image; and,
FIG. 4 is a back elevational view thereof.
The broken line showings of the stitching on the seat, the stitching on the
backrest, and the stitching and nail heads along the bottoms of the
armrests are for environmental purposes only and form no part of the
claimed design.