This produces exactly the same output (to the best of my ability to
determine) as github.com/golang/protobuf.
Change-Id: Ib60e7a836efb1eb0e5167b30458049ec239e7903
Reviewed-on: https://go-review.googlesource.com/134695
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
