This will let us use ANGLE formats to describe a format layout rather
than a Renderer-specific usage. This in turn will let us use ANGLE
formats for other Renderers, as a universal thing.

BUG=angleproject:1455

Change-Id: I56492cb809d4ef6ac4b962cb12affbc853bbdaa0
Reviewed-on: https://chromium-review.googlesource.com/365269Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>