When I saw that it was labelled "legacy", I went looking for users of it
to see how it was still used. But there aren't any. Save the next person
the trouble.

Change-Id: I921dd6c57b60331c9816542272555153ac133c02
Reviewed-on: https://go-review.googlesource.com/16035Reviewed-by: Dave Cheney <dave@cheney.net>
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>