"Everything at Google, from Search to Gmail, is packaged and run in a Linux container." Was this something which Google had previously disclosed? Seems a bit surprising to me.
I'm guessing you weren't aware that google is the company that wrote the overwhelming majority of the cgroup subsystem and much of the namespace bits that lxc/docker use. Paul Menage and Rohit something were the two biggest kernel guys on it if memory serves. I used to read the LKML firehose actively and gave up eventually.
Yes, we contributed the core cgroups system, and a good chunk of the memory and I/O cgroup subsystems. Google didn't have much need for namespacing though - when you have complete control over all the code that's running, it's possible to have the common libraries co-ordinating with the cluster management system to assign things like network ports and userids, so there's no need to virtualize IP addresses or userids. Google's containers are (or at least were - I left a few years ago) just for resource isolation.