Try again to put SkXfermode_opts in SK_OPTS_NS

src/core/SkOpts.cpp

Index: src/core/SkOpts.cpp
diff --git a/src/core/SkOpts.cpp b/src/core/SkOpts.cpp
index 772a059ce906e4ce81ddb46c5bec754d407b18fb..69373c0fd1abaa435d27c4febe342309cdf6c2bf 100644
--- a/src/core/SkOpts.cpp
+++ b/src/core/SkOpts.cpp
@@ -38,7 +38,7 @@ namespace SkOpts {
     decltype(rsqrt)                     rsqrt = sk_default::rsqrt;
     decltype(memset16)               memset16 = sk_default::memset16;
     decltype(memset32)               memset32 = sk_default::memset32;
-    decltype(create_xfermode) create_xfermode = SkCreate4pxXfermode;
+    decltype(create_xfermode) create_xfermode = sk_default::create_xfermode;
     decltype(color_cube_filter_span) color_cube_filter_span = sk_default::color_cube_filter_span;
 
     decltype(box_blur_xx) box_blur_xx = sk_default::box_blur_xx;