Updates #6465.

Change-Id: I5babbcf4c92dae47c823a41628b01e4ceb2332eb
Reviewed-on: https://go-review.googlesource.com/11951
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>