TEST=conformance2/rendering/fs-color-type-mismatch-color-buffer-type
BUG=angleproject:1688

Change-Id: I17848baf40b6d32b5adc1458fe2369b850164da3
Reviewed-on: https://chromium-review.googlesource.com/518246
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Frank Henigman <fjhenigman@chromium.org>