Automated refactoring produced using github.com/mdempsky/unconvert.

Change-Id: Iacf871a4f221ef17f48999a464ab2858b2bbaa90
Reviewed-on: https://go-review.googlesource.com/20071Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>