The ornamental design for a chimneycap, as shown and described.
FIG. 1 is a perspective view of an alternate embodiment of the chimney cap of our design shown in its ordinary environment, mounted on a chimney;
FIG. 2 is a side view of the alternate embodiment of the chimney cap of our design, the opposite side and the adjacent right and left sides being a mirror image;
FIG. 3 is a top view thereof; and,
FIG. 4 is a bottom view thereof.
The broken line showing of a chimney is included for the purpose of illustrating environmental structure and forms no part of the claimed design.