Passes toolstash-check.

Change-Id: I6a2d46e69d4d3a06858c80c4ea1ad3f5a58f6956
Reviewed-on: https://go-review.googlesource.com/103859
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>