Updated the FenceSync and FenceNV objects to use Error objects.

BUG=angle:520

Change-Id: I1e49b35905d8916baadb129c8aa58a11bd721500
Reviewed-on: https://chromium-review.googlesource.com/220781
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
Split combined declarations into separate statements.

BUG=415694

Change-Id: I7afb08a8a5ed10bbc6f7d23638daca6982f7c88b
Reviewed-on: https://chromium-review.googlesource.com/221455
Tested-by: Nicolas Capens <capn@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Perform short-circuit unfolding on separate declarations.

BUG=415694

Change-Id: I812abb21d2ab4af0b63631a23026d5860df61672
Reviewed-on: https://chromium-review.googlesource.com/221945
Tested-by: Nicolas Capens <capn@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>