From 16b1eab9bab992785a9c8dd780b42e6ed76a5dc0 Mon Sep 17 00:00:00 2001
From: Brian Salomon <bsalomon@google.com>
Date: Thu, 24 May 2018 16:08:28 -0400
Subject: [PATCH] Reland "Workaround constexpr bug in MSVC 2015 in GrTextureOp"

This is a reland of 9eff78e2623d600282ca63c2e9988e0ffbba2949

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>

Change-Id: I90e5d807f658baadfab80333d84872d8105bf02b
Reviewed-on: https://skia-review.googlesource.com/130306
Reviewed-by: Stephen White <senorblanco@chromium.org>
---
 src/gpu/ops/GrTextureOp.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/gpu/ops/GrTextureOp.cpp b/src/gpu/ops/GrTextureOp.cpp
index 933a17393e..4d0c41d127 100644
--- a/src/gpu/ops/GrTextureOp.cpp
+++ b/src/gpu/ops/GrTextureOp.cpp
@@ -790,9 +790,14 @@ __attribute__((no_sanitize("float-cast-overflow")))
             ih[t] = 1.f / texture->height();
         }
 
+#if defined(_MSC_VER) && _MSC_VER <= 1910
+#   define MAYBE_CONSTEXPR const
+#else
+#   define MAYBE_CONSTEXPR constexpr
+#endif
         using TessFn =
                 decltype(&TextureOp::tess<SkPoint, MultiTexture::kNo, Domain::kNo, GrAA::kNo>);
-        static constexpr TessFn kTessFns[] = {
+        static MAYBE_CONSTEXPR TessFn kTessFns[] = {
                 &TextureOp::tess<SkPoint,  MultiTexture::kNo,  Domain::kNo,  GrAA::kNo>,
                 &TextureOp::tess<SkPoint,  MultiTexture::kNo,  Domain::kNo,  GrAA::kYes>,
                 &TextureOp::tess<SkPoint,  MultiTexture::kNo,  Domain::kYes, GrAA::kNo>,
@@ -810,6 +815,7 @@ __attribute__((no_sanitize("float-cast-overflow")))
                 &TextureOp::tess<SkPoint3, MultiTexture::kYes, Domain::kYes, GrAA::kNo>,
                 &TextureOp::tess<SkPoint3, MultiTexture::kYes, Domain::kYes, GrAA::kYes>,
         };
+#undef MAYBE_CONSTEXPR
         int tessFnIdx = 0;
         tessFnIdx |= coverageAA      ? 0x1 : 0x0;
         tessFnIdx |= fDomain         ? 0x2 : 0x0;