What is this chrome BMX?

Bog-standard BMX, probably Chinese, likely from a department store. The brake is a touch fancy but nothing else is remarkable.

Rear wheel is also way too far forward, possibly the chain is elongated or even just too long given the mount of droop.

Can't really see, but the front rim looks more worn than the rear, suggesting there may have been a front brake which was removed possibly ?

Top part of headset looks wrong - perhaps plastic.

There's also rust in most of the welds, it needs a decent clean and some kind of rust treatment.

The rear brake caliper kind-of looks like a dual pivot, but may be some kind of U brake. The brake is cable tied down the top tube, and combined with the angle of the outer cable suggest the rear brake is not original.

^{(not a great answer sorry, but too long for a comment)}

It looks like an eminently-restorable bike, and you will not have to spend a lot on parts, just clean-up and preserve what's there now.