The ornamental design for a chair, as shown and described.
FIG. 1 is a perspective view of a chair showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear perspective view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is the opposite side view of FIG. 4 thereof;
FIG. 6 is a rear view thereof;
FIG. 7 is a top view thereof; and,
FIG. 8 is a bottom view thereof.
The fragmented crosshatching shown on the backrest member is understood to represent fabric and would be continuous throughout the circumscribed areas.
The broken lines showing on the FIG. 8 bottom view are for illustrative purposes only and form no part of the claimed design.