His own, of course.
By allowing the FBI to indict Hillary, Obama retains his control over the party and gains control over the Clintons.
The indictment will come with a pre-agreed pardon (for Hillary AND Bill), to be executed in January, 2017. Whereupon, Hillary will step down...and support the transfer of her delegates to Biden. Wi8th his surrogate in place, Obama retains effective control of the party.
With the promise of a pardon, Obama has gained control over the Clintons -- and there will be mutual pledges to keep lips sealed (about Benghazi and sundry corruptions).
Your scenario leaves out the most important item. The US Constitution provides for a vice president.