The ornamental design for electronic device holder, as shown and described.
FIG. 1 is a top, front, left side view perspective view of an electronic device holder showing the new design;
FIG. 2 is a front elevation view of the embodiment;
FIG. 3 is a rear elevation view of the embodiment;
FIG. 4 is a right side view of the embodiment;
FIG. 5 is a left side view of the embodiment;
FIG. 6 is a top plane view of the embodiment;
FIG. 7 is a bottom plane view of the embodiment;
FIG. 8 is a closed, front view of the embodiment;
FIG. 9 is a open, front view of the embodiment; and,
FIG. 10 is an additional front, open view (with partial insert and shown in phantom) of the embodiment.
The dot-dashed broken lines representing an electronic device and a binder are for the purposes of illustrating environment and form no part of the claimed design. The evenly spaced broken lines represent stitching and are part of the claimed design.