Passes toolstash-check.

Change-Id: Idc00f15e369cad62cb8f7a09fd0ef09abd3fcdef
Reviewed-on: https://go-review.googlesource.com/109356
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>