Updates #29087

Change-Id: I0bab45818119176c2ba5de9c0e457b7717485d6f
Reviewed-on: https://go-review.googlesource.com/c/152162
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>