Cover for Electronic Device

FIG. 1 is a perspective view of a cover for electronic device showing my new design; FIG. 2 is a front view thereof; FIG. 3 is a rear view thereof; FIG. 4 is a left side view thereof; FIG. 5 is a right side view thereof; FIG. 6 is a top view thereof; FIG. 7 is a bottom view thereof; FIG. 8 is a first reference perspective view showing usage state thereof; FIG. 9 is a second reference perspective view showing usage state thereof; and, FIG. 10 is an enlarged view of the area of FIG. 8 . The broken lines depict portions of the cover for electronic device that form no part of the claimed design.