These are now unused.

Updates #11970.

Change-Id: I43e5c4e5bcda9581bacc63364f96bb4855ab779f
Reviewed-on: https://go-review.googlesource.com/16393Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>