The ornamental design for a chair, as shown and described.
FIG. 1 is a front right perspective view of a first embodiment of a chair showing our new design;
FIG. 2 is a rear right perspective view thereof;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a rear elevation view thereof;
FIG. 5 is a right side elevation view thereof, the left side view being a mirror image;
FIG. 6 is a top plan view thereof;
FIG. 7 is a front right perspective view of a second embodiment of a chair showing our new design;
FIG. 8 is a rear right perspective view thereof;
FIG. 9 is a front elevation view thereof;
FIG. 10 is a rear elevation view thereof;
FIG. 11 is a right side elevation view thereof, the left side view being a mirror image; and,
FIG. 12 is a top plan view thereof.
The chair is shown in FIGS. 7-12 with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.