Update the format table to check support for filtering and rendering.

Since filerability and renderability may depend on separate extensions,
use functions to determine their support.  Context now uses these
functions to fill it's own TextureFormatCaps.

BUG=angle:658

Change-Id: Ib4dc877ba7c24f84a3823fd5aa2e01a3b3621705
Reviewed-on: https://chromium-review.googlesource.com/206831
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Brandon Jones <bajones@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
6 files changed