The ornamental design for a plunger for toilet, as shown and described.
FIG. 1 is a top plan view of a plunger for toilet showing my new design.
FIG. 2 is a bottom view thereof; and
FIG. 3 is a front view thereof.
FIG. 4 is a rear view thereof;
FIG. 5 is a side view thereof; and,
FIG. 6 is a perspective view thereof.
The broken line showing of details in FIGS. 1-6 is included for the purpose of showing environmental portions of the plunger for toilet and forms no part of the claimed design. The broken boundary line near the perimeter of the design in FIG. 2 indicates the boundaries of the claim, and also forms no part of the claimed design.