The ornamental design for a chair, as shown and described.
FIG. 1 is a front perspective view of a chair showing, in particular, the ornamental design thereof.
FIG. 2 is a rear perspective view of the chair of FIG. 1.
FIG. 3 is a right side view of the chair of FIG. 1.
FIG. 4 is a left side view of the chair of FIG. 1
FIG. 5 is a left rear end view of the chair of FIG. 1. It will be understood that a right rear end view is a mirror image of the left rear end view; and,
FIG. 6 is a top plan view of the chair of FIG. 1.
It will be understood that the bottom of the chair is flat and unornamented and/or not visible during normal use.