Follow the convertion (https://golang.org/s/generatedcode) for generated
code.

Change-Id: I4ac8b99ac45f25dd2399d048ea831489e5394984
Reviewed-on: https://go-review.googlesource.com/118821
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>