Updates #17243

Change-Id: Iaa737874e75fdac73452f1fc13a5749e8df78ebe
Reviewed-on: https://go-review.googlesource.com/33332
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>