Non-responsive Programs

So, I have a window on my Macbook Air that doesn't want to close, anytime I move over the red circle to close out, it just shows the cursor as loading. I'm not sure if it's relevant, but it may be some Itunes Store (online) window or Google Chrome because at my college you need to sign into the wifi, so often times my Mac will pop up an Itunes window prompting me to sign on (but you sign in using the internet I believe, not entirely sure).

Regardless, I went into the task manager ti try to force close the application, but I couldn't find it. I force closed everything except Finder and Google Chrome , so I also am afraid if it's somehow a Chrome window I'd need to force close all of my Chrome windows to close it.

Any help would be appreciated.