Automated refactoring using gorename, eg, and gofmt -r.

Passes toolstash-check.

Change-Id: Ib50f368bf62a07e5ced50b1b92a29c669ba9a158
Reviewed-on: https://go-review.googlesource.com/41401
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>