Passes toolstash-check -all.

Change-Id: Ic9eb0c52bedac185ab86cc62207f199d93700344
Reviewed-on: https://go-review.googlesource.com/39795
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>