The ornamental design for hook for chair, as shown and described.
FIG. 1 is a perspective view of a portion of a hook for a chair in accordance with the present invention, mounted to a chair show in broken line for environmental purposes only;
FIG. 2 is a perspective view of a hook for a chair in accordance with the present invention;
FIG. 3 is a rear view of the hook of FIG. 2;
FIG. 4 is a side view of the hook of FIGS. 2-3;
FIG. 5 is a front view of the hook of FIGS. 2-4;
FIG. 6 is a side view of the hook of FIGS. 2-5 showing the opposite side from FIG. 4;
FIG. 7 is a bottom view of the hook of FIGS. 2-6; and,
FIG. 8 is a top view of the hook of FIGS. 2-7.
The broken lines showing a chair and hole openings are for the purposes of illustrating environment and form no part of the claimed design.