Earlier quoted context omitted.
Just wondering, which DSLR in particular?
it's not a DSLR, but some recent Panasonic mirrorless cameras have this https://www.panasonic.com/global/consumer/lumix/feature/post...
The new “Dual Pixel AF” sensors in some newer Canon DSLRs is much more like the Lytro, in that focus can be adjusted slightly in a single image capture, no burst capture trickery.