This isn’t actually clear. GrubHub’s about page:
“ Grubhub is a leading online and mobile food-ordering and delivery marketplace with the largest and most comprehensive network of restaurant partners. ”
This tells me as a customer that the restaurant is a consenting partner. This is a lie.
EDIT: a commentor below had issue with my use of the word lie here. To clarify, I meant that this is not a clear disclaimer.