This mirrors the spec naming and makes auto-gen a little easier.

BUG=chromium:697758

Change-Id: I9bcbc2c874b9a93a6d542aedf2b239f01ee708ce
Reviewed-on: https://chromium-review.googlesource.com/526393Reviewed-by: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>