Meaning of “China(ちな)”

“China(ちな)” is an abstraction for “Chinamini(ちなみに)” which means “by the way” or “in passing” or so and this word has no relationship with China and pronunciation is different.
This is a slang among young.

Example Conversation

A: Are you free tomorrow?
B: Yep, I’m free.
A: Then let’s go hang out.
B: OK. China(ちな) can I invite C too?

A: あした予定空いてるんだっけ？
B: あいてるよー
A: そしたら遊びにいこうぜ
B: OK。ちな、Cもよんでいい？