The ornamental design for a chair, as shown and described.
FIG. 1 is a perspective view of a chair showing my ornamental design.
FIG. 2 is a front view of the chair of FIG. 1.
FIG. 3 is a side view of the chair of FIG. 1, the opposite side being a mirror image thereof.
FIG. 4 is a back view of the chair of FIG. 1.
FIG. 5 is an enlarged detail view showing a portion of an armrest of the chair of FIG. 1, the opposite armrest being a mirror image thereof; and,
FIG. 6 is an enlarged detail view showing a portion of a back support of the chair of FIG. 1, the opposite side of the back support being a mirror image thereof.