OK I did some more research and it looks like it's just trying to load an image from there. You can easily just AdBlock the address.
This is what it's trying to load:
Just add the address as a filter in AdBlock:
https://chatenabled.mail.google.com/*
AdBlock will strip/block the address before the browser tries to load the page so no hit will be registered.
If you're not running Firefox (or Portable Firefox if it's not installed on the machine...) then I don't have a solution.