Passes toolstash-check.

Change-Id: I804e73447b6fdbb75af6235c193c4ee7cbcf8d3a
Reviewed-on: https://go-review.googlesource.com/105045
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>