Chrome DNS prefetching & TCP pre-connect
http://www.igvita.com/2012/06/04/chrome-networking-dns-prefetch-and-tcp-preconnect/
Excerpts from above website:
Each browser tab in Chrome is its own isolated process, which gives us great isolation and many security benefits.
An average DNS lookup takes 60~120ms, followed by a full round-trip (RTT) to perform the TCP handshake - combined, that creates 100-200ms of latency before we can even send the request!
chrome://network-action-predictor - omnibox predictor stats (tip: check 'Filter zero confidences')
chrome://net-internals/#sockets - current socket pool status
chrome://net-internals#dns - Chrome's in-memory DNS cache
chrome://histograms/DNS - histograms of your DNS performance
chrome://dns - startup prefetch list and subresource host cache