There is nothing in your post which would support a case of unlawful discrimination. The only hint of discriminatory intent is the comment your boss made that he laid someone off who was of the same ethnic group. It will take more than that to make a case that you are the victim of unlawful discrimination.
If you can articulate a factual basis to support your belief that this person is discriminating against you due to your ethnicity, you need to discuss this with an employment law attorney for a case analysis. Do not do so on an open internet forum.
In the meantime, do not quit. If you disagree with your performance review, write a detailed, fact based response and ask that it be reviewed by a higher manager and placed in your personnel file. Do the best job you can and do not give this boss a reason to fire you until you figure out, with the help of an attorney, what you want to do.
They say you get what you pay for, and this response is free, so take it for what it is worth. This is my opinion based on very limited information. My opinion should not be taken as legal advice. For true advice, we would require a confidential consultation where I would ask you questions and get your complete story. This is a public forum, so remember, nothing here is confidential. Nor am I your attorney. I do not know who you are and you have not hired me to provide any legal service. To do so would require us to meet and sign written retainer agreement. My responses are intended for general information only.
California law specifically provides protection from harassment or discrimination in employment because of: Age (40 and over); Ancestry; Color; Religious Creed (including religious dress and grooming practices); Denial of Family and Medical Care Leave; Disability (mental and physical) including HIV and AIDS; Marital Status; Medical Condition (cancer and genetic characteristics); Genetic Information; National Origin (including language use restrictions); Race; Sex (which includes pregnancy, childbirth, breastfeeding and medical conditions related to pregnancy, childbirth or breastfeeding); Gender, Gender Identity, and Gender Expression; and Sexual Orientation. If you feel that you were discriminated on the basis of any of the areas listed above you should contact a employment attorney in your area.