Updates #18609

Change-Id: I8306135660f52cf625bed4c7f53f632e527617de
Reviewed-on: https://go-review.googlesource.com/35265
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Quentin Smith <quentin@golang.org>