TL;DR: I have been unable to locate any instances of a Robin uniform being spray-painted. That said, the scene in question is most likely a nod to long-time images associated with the characters.
The idea of a Robin suit on display has been long associated with Batman. It became a prominent sight/trope with the character following the death of the second Robin - Jason Todd - in the "A Death in the Family" arc of 1989. Afterwards, Batman kept the suit on display in the Bat-Cave not only as a tribute to the fallen sidekick, but also as a constant reminder to himself of the price his crusade has cost himself & others.
The Joker, on the other hand, has long been associated with graffiti and vandalism. This trope was used in 1989's "Batman", with Jack Nicholson's Joker often vandalizing art, decor, and even his own girlfriend - continuously putting his own unique "spin" on the valued objects of others. The association was used heavily in the marketing for 2008's "The Dark Knight" as well, with much of the marketing material for the Joker character revolving around playing cards & graffiti.
Without context, it's impossible to know what the scene means within the DC Cinematic Universe. We know that Batman is considered by most to be an urban legend, despite operating in Gotham for years. Therefore, we can assume that the Robin suit isn't being displayed in public. That means we can speculate a couple of possible meanings:
- The suit was spray-painted that way when Batman found Robin dead, and Batman keeps it as is to remind himself of Joker's depravity.
- The suit was NOT vandalized before this scene, so Batman finding it vandalized like this indicates to him (and the audience) that The Joker has found his way into the Batcave somehow... or wherever it is that Batman keeps the suit.
Hopefully we'll have a better answer regarding the graffiti and its meaning once the film is released next year.