When Chinito is used as a slang term the meaning can be term of endearment, or just general hyperbolic description. -ito -ita is often used as adjunctive to Spanish words to make them more informal and endearing, not necessarily (or likely) meant literally commenting on size in a deragatory way.
BF: Que tal, mi amor pequeñita (Sup, my little love)
friend1: How was NY?
friend2: ...in Chinatown i was the only one not Chinito there!
Mom1: ...she's 2months old now
Mom2: aww! Que linda! Look at this preciosa chinita!
Punani (Mexican) : Sup?
Lil' Chinito Lokz (Asian): Hey buddy.
Chinito: "Look at yourself dirty brown dwarf. At least we have basektball players in the US. No such a thing as a tall mexicunt like you. Go eat a burrito with your hands."
Lil' Asian Kid:" i hope they don't put tacos up my ass again. that fucking hurt"
Chinese guy: Hey wetback my penis is not THAT small!