Revert "Workaround constexpr bug in MSVC 2015 in GrTextureOp"

This reverts commit 9eff78e2623d600282ca63c2e9988e0ffbba2949.

Reason for revert: Possibly blocking Chromium roll (layout tests)

Original change's description:
> Workaround constexpr bug in MSVC 2015 in GrTextureOp
> 
> Change-Id: I441858aab5fcd63e5467625a23681c5bcd35f25b
> Reviewed-on: https://skia-review.googlesource.com/130122
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: Brian Salomon <bsalomon@google.com>

TBR=bsalomon@google.com,brianosman@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I4cf8f2b86cc601cf649e23e3889150419a834cb1
Reviewed-on: https://skia-review.googlesource.com/130303
Reviewed-by: Stephen White <senorblanco@chromium.org>
Commit-Queue: Stephen White <senorblanco@chromium.org>
1 file changed