This query is currently a part of a std::map. Split it off to its
own switch using auto-generation based on the format string.

Also introduce a DXGI-to-angle format map. This map is not totally
complete because some more esoteric formats don't have corresponding
ANGLE formats yet. We should add these other formats (EG NV12) if we
need them.

BUG=angleproject:1389
BUG=angleproject:1459

Change-Id: I49e045bdc04a52166299c9e22a4c4d3f24069dbc
Reviewed-on: https://chromium-review.googlesource.com/392209Reviewed-by: Geoff Lang <geofflang@chromium.org>