My solution is to use a firewall with per-application rules and just turn off network access for chrome before I launch it. On my laptop I just unplug the wired/wireless network for during the launch. This was mainly because of HN but also has the added benefit of taking less system resources since a blank page typically is less resource hungry than a real page.
Firefox has a better solution for this but then again, I don't use firefox.
Firefox has a better solution for this but then again, I don't use firefox.