From Nico Weber (Chromium developer): http://groups.google.com/a/chromium.org ... 58e6015fc5
If you type in a single-word search query, chrome needs to send a DNS request to check if this might be a single-word host name: For example, "test" might be a search for "test" or a navigation to "http://test". If the query ends up being a host, chrome shows an infobar that asks "did you mean to go to 'test' instead". For perf reasons, the dns query needs to be asynchronous.
Now some ISPs started showing ads for non-existent domain names ( http://en.wikipedia.org/wiki/DNS_hijacking
), meaning chrome would always show that infobar for every single-word query. Since this is annoying, chrome now sends three random DNS requests at startup, and if they all resolve (to the same IP, I think), it now knows not to show the "did you mean" infobar for single-word queries that resolve to that IP.