Any gambler who has long experience, is in control, and is not easily swayed by emotion can be called a professional gambler. I believe this does not limit a person to skill-based gambling.
On the other hand, if you feel that a professional is someone that wins more than losing in the long run, I don't think that we have someone like that. This is because, he will definitely be an addict which kills all the skills, fun and profits.
It might be difficult to find a gambler who is on a positive in his entire gambling career but I would not say that this person can be an addict since winnings and being an addict is two different scenarios. Besides, gambling addicts are moving towards financial ruin, which we can conclude that gambling addicts are bound to lose everything, so saying that a gambler is a gambling addict because he is winning has a huge flaw.