Chalkline holder

FIG. 1 is an end, front, and side perspective view of my design for a chalkline holder;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is an elevation view thereof from the same side as in FIG. 1;

FIG. 5 is an elevation view thereof from the side opposite that in FIG. 1;

FIG. 6 is an elevation view thereof from the same end as in FIG. 1; and,

FIG. 7 is an elevation view thereof from the end opposite that in FIG. 6.

The portions of the chalkline holder shown in dotted lines do not consitute a part of the claimed design.