CL generated mechanically with github.com/mdempsky/unconvert.

Change-Id: Ic590315cbc7026163a1b3f8ea306ba35f1a53256
Reviewed-on: https://go-review.googlesource.com/22103
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>