The patch extends glGetIntegerv and glGetFramebufferAttachmentParameteriv
logic to handle the new tokens from the ANGLE_multiview extension.

BUG=angleproject:2062
TEST=angle_end2end_tests

Change-Id: Ide145279cd7b58cd03502458d7d3a1a0f5e9e86d
Reviewed-on: https://chromium-review.googlesource.com/573780Reviewed-by: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>