[x/blog] go.blog: refer to the Google Cloud Platform
[x/blog] go.blog: refer to the Google Cloud Platform

R=golang-dev
CC=golang-dev
https://golang.org/cl/10225043
X-Blog-Commit: 7e13a0d474457bc5931a8b202bac0a3036a7ea26

golang/website,golang/website,golang/website,golang/website,golang/website,golang/website,golang/website