FIG. 1 is a perspective view showing the top, front and left and right sides of a chair base which forms my new design;
FIG. 2 is a bottom view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a front elevational view thereof;
FIG. 5 is a rear elevational view thereof;
FIG. 6 is a left side elevational view thereof; and,
FIG. 7 is a right side elevational view thereof.