I wouldn't say the question is too localized simply because the asker says "it doesn't work". The FAQ makes it clear that questions should be about a real, actual problem that you're facing. The problem should of course be something that a wider audience should also experience, but a comment doesn't make a post too localized, as too localized is for questions that are so rare that no one else will be helped by it.
With that said, the user is trying to draw you in to help you solve the actual integration of your answer, which is too localized, but that doesn't make the original question too localized. Read on...
In this case, the problem is that the asker is looking for a cut and paste solution, which again isn't a problem with the question but instead is a problem with the asker. What you're dealing with in these situations is a help vampire, and this type of help vampire preys on you by posting what looks like a nice question. However, instead of actually using your answer to help that person get past a blocker he/she is facing, he/she instead tries to get you to do his/her work by reeling you in to actually help him or her implement the solution.
Unlike Amy Hoy, I use he or she because I've seen plenty of female help vampires as well! They do exist Amy! :)
In this situation, you might help the vampire, er user, with maybe a follow up question and a clarifying edit to your answer, but if that person keeps saying "I tried to put in that semicolon as you suggested, but it's still not working, then say something like this:
The code I provided you will establish video using WebRTC, and it answers your original question about how to get the ICE candidates to avoid throwing the DOM Exceptions; however, you're now at the point where you just need to take the solution I've provided and use your debugger to get past the more common errors that we all encounter when integrating code. You can do this! Be sure to let us know how this works out. Good luck! :)
By being encouraging and positive, you can escape the help vampire while also encouraging this person to be more self-reliant, which helps create better Stack Overflow users.
To be clear, this type of help vampire doesn't know he/she is being a help vampire, and may actually be a good programmer most of the time, but is maybe feeling a bit overwhelmed. Encouragement and positivity is the cure for this form of help vampirism!