net: add deadline prolongation test Currently the test exposes data races on deadline vars.
net: add deadline prolongation test
Currently the test exposes data races on deadline vars.

R=golang-dev, dave, bradfitz, rsc
CC=golang-dev
http://codereview.appspot.com/6845091

h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang