What is claimed is the ornamental design for a combined grease tray and control knobs for a griddle, as shown and described.
FIG. 1 is a top front perspective view of a combined grease tray and control knobs for a griddle.
FIG. 2 is a front elevation view thereof.
FIG. 3 is a rear elevation view thereof.
FIG. 4 is a left side elevation view thereof.
FIG. 5 is a right side elevation view thereof.
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines shown in the drawings depict portions of the combined grease tray and control knobs for a griddle that form no part of the claimed design and illustrate environment that forms no part of the claimed design.