Chester Nogura, also known as "Whitey", was a member of Griff's gang. Being Japanese-American, he was the first non-Caucasian member of any Tannen gang in known Hill Valley history
As with other members of the Tannen gangs, he's not referred to by name in the dialogue, although he is listed as "Whitey" in the credits, and Chester Nogura in the text of the USA Today article.
Appropriately enough, Whitey's hoverboard has a design of a Rising Sun , the emblem of Japan.
The nickname "Whitey" may have been a reference to Leave it to Beaver, which had a bully character nicknamed Whitey.