cmd/api: add missing runtime struct Fixes build.
cmd/api: add missing runtime struct
Fixes build.

TBR=khr
R=golang-codereviews
CC=golang-codereviews, khr
https://codereview.appspot.com/130390044

tv42/old-go,tv42/old-go,tv42/old-go,tv42/old-go,tv42/old-go,tv42/old-go,tv42/old-go