No behavior change.

Change-Id: I595c15ee976adf21bdbabdf24edf203c9e446185
Reviewed-on: https://go-review.googlesource.com/36958Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>