CONTRIBUTORS: John DeNero, Sameer Ajmani (Google CLA)
CONTRIBUTORS: John DeNero, Sameer Ajmani (Google CLA)

R=golang-dev, gri
CC=golang-dev
http://codereview.appspot.com/4274079
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go