You are only eligible to collect unemployment benefits when you are totally or partially unemployed. This means that you have to be permanently laid off or your hours permanently reduced to part time. In practice, the state makes you wait for two full weeks without work before your benefits will kick in.
Your employer has the right to force you to take days off as vacation, whether paid or unpaid, if your employment is at-will (which is the usual case). Taking a few extra unpaid days in December will likely not qualify you for unemployment benefits as you do not seem to be permanently partially unemployed. If you have any doubts, contact the Unemployment Insurance Office (http://www.edd.ca.gov/Unemployment/Eligibility.htm) to discuss your rights with a qualified state agent.
Disclaimers: I am not your attorney and the information provided in this response is for general public informational purposes only. It does not constitute legal advice and I am under no duty to represent you or keep our communications confidential. My answers on Avvo may constitute Attorney Advertising under California law.