I saw this late night while I was on my computer and had my TV going in the background. it was an animated film where Bruce was old and had since retired resulting in the crime rate in Gotham rising.
At the start there is a shot of what I believe is Arkham Asylum, where The Joker is apparently in a vegetable state and Harvey Dent has just came out of facial surgery now having both sides of his face match (and normal).
Bruce decides to become Batman again and in one of his acts he saves two women from a group who are apart of a gang called the Mutants whose leader keeps putting out videos threatening to kill Gordon.
Harvey Dent, after coming out and saying he's going to try and turn over a new leaf goes to blow up the "life bank" and he has his face totally wrapped in bandages and both sides of his coins are now scratched which makes Batman think he's now doing self-half. when he encounters Harvey and takes off the bandages it's shown he hasn't been self-harming and in fact he still looks normal but there's a flash of Harvey's face as if both sides had been scarred, showing that Harvey doesn't believe he's been fixed, and when "both sides match" he's believing that his face is fully scarred. When there's a new report on Harvey being taken in and Batman is mentioned there is signs of movement from The Joker.
At some point one of the girls Batman saved from The Mutants puts on a Robin Costume and follows Batman who is driving a tank to the scrap/junk yard. There it turns into a little one-sided war with the Mutants using every piece of military hardware they have to stop Batman but in the end being decimated leaving only the leader who is wearing a visor similar to what Cyclops wears in X-Men.
During the fight, Batman has his butt handed to him, and the leader of the Mutants is about to finish him when the female Robin jumps on his back. The distraction is enough for Batman to recover and throw something sticky at the leader's face, which covers it and appears to suffocate him.
That's about all I remember of it.