If can declare Done, then merge & start using.
Background (from Dec 8, 2014 IRC chat with Andrew):
- currently, X-Analytics fields are mostly added by varnish which is difficult to make changes to since it is critical ops production infrastructure
- researchers really want to be able to put more info into the X-Analytics header
- this is field in the webrequest logs that it is easy for us to add info into, without having to modify logging format. Specifically, they really want something like: page_id=X, and other things.
Benefit of change:
it makes it easier to support requests like the researchers really want