The closest match I know of is the "To Kill a Legend" storyline from Detective Comics Vol 1 500. In that issue, the Phantom Stranger takes Batman and Robin into a world where time has moved differently, and his parents have not yet been gunned down. Batman faces the decision of whether he should save this alternate set of parents, knowing that that would mean no Batman, someone who has saved thousands of lives over the years. Complicating things, a bit of research shows that this world lacks any heroes, to the point that they don't even have mythological heroes. And, of course, it's barely even a question as to what he decides.

Despite the moral conflicts of the whole ordeal, Batman's intervention causes the event in which the Waynes are killed, although Chill is now not part of the event. Realizing his mistake, Batman saves the Waynes and a young version of himself, who was a spoiled and obnoxious little kid. Having saved the Waynes, the Phantom Stranger returns the heroes to their own world, but the deed has changed the young Bruce Wayne's life, who now changes his demeanor and wants to become the "Bat Creature" who saved them. The Batman will exist, although this time is not because of vengeance, but for a rather inspiring motivation.


There's an interesting analysis of the storyline here, which harps on the whole "no concept of a hero" thing, and how it beggars belief.