Updates #14518.

This reverts commit 3e9264c9.

Change-Id: I2531b04efc735b5b51ef675541172f2f5ae747d9
Reviewed-on: https://go-review.googlesource.com/22836Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>