The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of a tire including the tire tread of the present application taken generally from the front and a first side of the tire;
FIG. 2 is a front view thereof;
FIG. 3 is side view thereof;
FIG. 4 is an enlarged, partial perspective view thereof;
FIG. 5 is an enlarged, partial front view thereof; and,
FIG. 6 is an enlarged, partial side view thereof.
The broken-lines in the drawings show portions of the article that form no part of the claim.