Refactor to put SkXfermode_opts inside SK_OPTS_NS.

Without this refactor I was getting warnings previously about having code
inside namespace SK_OPTS_NS (e.g. namespace sse2, namespace neon) referring to
code inside an anonymous namespace (Sk4px, SkPMFloat, Sk4f, etc) [1].

That low-level code was in an anonymous namespace to allow multiple independent
copies of its methods to be instantiated without the linker getting confused /
offended about violating the One Definition Rule.  This was only happening in
Debug mode where the methods were not being inlined.

To fix this all, I've force-inlined the methods of the low-level code and
removed the anonymous namespace.

BUG=skia:4117

[1] Here is what those errors looked like:

In file included from ../../../../src/core/SkOpts.cpp:18:0:
../../../../src/opts/SkXfermode_opts.h:193:7: error: 'portable::Sk4pxXfermode' has a field 'portable::Sk4pxXfermode::fProc4' whose type uses the anonymous namespace [-Werror]
 class Sk4pxXfermode : public SkProcCoeffXfermode {
       ^
../../../../src/opts/SkXfermode_opts.h:193:7: error: 'portable::Sk4pxXfermode' has a field 'portable::Sk4pxXfermode::fAAProc4' whose type uses the anonymous namespace [-Werror]
../../../../src/opts/SkXfermode_opts.h:235:7: error: 'portable::SkPMFloatXfermode' has a field 'portable::SkPMFloatXfermode::fProcF' whose type uses the anonymous namespace [-Werror]
 class SkPMFloatXfermode : public SkProcCoeffXfermode {
       ^
cc1plus: all warnings being treated as errors

Review URL: https://codereview.chromium.org/1286093004

4 files changed, 1 insertions, 28 deletions

diff --git a/src/core/Sk4px.h b/src/core/Sk4px.h
index ffde1af504..1c8ed0df71 100644
--- a/src/core/Sk4px.h
+++ b/src/core/Sk4px.h
@@ -12,13 +12,6 @@
 #include "SkColor.h"
 #include "SkColorPriv.h"
 
-// This file may be included multiple times by .cpp files with different flags, leading
-// to different definitions.  Usually that doesn't matter because it's all inlined, but
-// in Debug modes the compilers may not inline everything.  So wrap everything in an
-// anonymous namespace to give each includer their own silo of this code (or the linker
-// will probably pick one randomly for us, which is rarely correct).
-namespace {
-
 // 1, 2 or 4 SkPMColors, generally vectorized.
 class Sk4px : public Sk16b {
 public:
@@ -226,8 +219,6 @@ private:
     typedef Sk16b INHERITED;
 };
 
-}  // namespace
-
 #ifdef SKNX_NO_SIMD
     #include "../opts/Sk4px_none.h"
 #else
diff --git a/src/core/SkNx.h b/src/core/SkNx.h
index 84f9b69353..728e450ebb 100644
--- a/src/core/SkNx.h
+++ b/src/core/SkNx.h
@@ -17,13 +17,6 @@
 #include <math.h>
 #define REQUIRE(x) static_assert(x, #x)
 
-// This file may be included multiple times by .cpp files with different flags, leading
-// to different definitions.  Usually that doesn't matter because it's all inlined, but
-// in Debug modes the compilers may not inline everything.  So wrap everything in an
-// anonymous namespace to give each includer their own silo of this code (or the linker
-// will probably pick one randomly for us, which is rarely correct).
-namespace {
-
 // The default implementations just fall back on a pair of size N/2.
 
 template <int N, typename T>
@@ -252,8 +245,6 @@ protected:
     T fVal;
 };
 
-}  // namespace
-
 // Include platform specific specializations if available.
 #ifndef SKNX_NO_SIMD
     #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2
diff --git a/src/core/SkOpts.cpp b/src/core/SkOpts.cpp
index 2bfc1af899..986c7cf6a8 100644
--- a/src/core/SkOpts.cpp
+++ b/src/core/SkOpts.cpp
@@ -37,7 +37,7 @@ namespace SkOpts {
     decltype(rsqrt)                     rsqrt = portable::rsqrt;
     decltype(memset16)               memset16 = portable::memset16;
     decltype(memset32)               memset32 = portable::memset32;
-    decltype(create_xfermode) create_xfermode = SkCreate4pxXfermode;
+    decltype(create_xfermode) create_xfermode = portable::create_xfermode;
 
     decltype(box_blur_xx) box_blur_xx = portable::box_blur_xx;
     decltype(box_blur_xy) box_blur_xy = portable::box_blur_xy;
diff --git a/src/core/SkPMFloat.h b/src/core/SkPMFloat.h
index f97f25c9c6..7db689917e 100644
--- a/src/core/SkPMFloat.h
+++ b/src/core/SkPMFloat.h
@@ -13,13 +13,6 @@
 #include "SkColorPriv.h"
 #include "SkNx.h"
 
-// This file may be included multiple times by .cpp files with different flags, leading
-// to different definitions.  Usually that doesn't matter because it's all inlined, but
-// in Debug modes the compilers may not inline everything.  So wrap everything in an
-// anonymous namespace to give each includer their own silo of this code (or the linker
-// will probably pick one randomly for us, which is rarely correct).
-namespace {
-
 // A pre-multiplied color storing each component in the same order as SkPMColor,
 // but as a float in the range [0, 1].
 class SkPMFloat : public Sk4f {
@@ -59,8 +52,6 @@ private:
     typedef Sk4f INHERITED;
 };
 
-}  // namespace
-
 #ifdef SKNX_NO_SIMD
     // Platform implementations of SkPMFloat assume Sk4f uses SSE or NEON.  _none is generic.
     #include "../opts/SkPMFloat_none.h"