No, working through your meal period does not entitle you to leave work early prior to your scheduled quitting time.
In California, in order for an “on duty” meal period to be allowed under California law, the nature of the work must actually prevent the employee from being relieved of all duty, and there must be a written agreement that an on-the-job paid meal period is agreed to.
Also the written agreement must state that the employee may, in writing, revoke the agreement at any time.
David Payab, Esq. from The Law Offices of Payab & Associates can be reached @ (818) 918-5522 or by visiting http://payablaw.com/