Try again to put SkXfermode_opts in SK_OPTS_NS

src/opts/SkXfermode_opts.h

Index: src/opts/SkXfermode_opts.h
diff --git a/src/opts/SkXfermode_opts.h b/src/opts/SkXfermode_opts.h
index b9d5db3042e3c348292f9b0a83fc37900fe5d135..b4fc8e1017a33009912bc4c2e1d9b8538aabd32d 100644
--- a/src/opts/SkXfermode_opts.h
+++ b/src/opts/SkXfermode_opts.h
@@ -12,7 +12,7 @@
 #include "SkPMFloat.h"
 #include "SkXfermode_proccoeff.h"
 
-namespace /* TODO: SK_OPTS_NS */ {
+namespace {
 
 // Most xfermodes can be done most efficiently 4 pixels at a time in 8 or 16-bit fixed point.
 #define XFERMODE(Name) static Sk4px SK_VECTORCALL Name(Sk4px s, Sk4px d)
@@ -274,7 +274,11 @@ private:
     typedef SkProcCoeffXfermode INHERITED;
 };
 
-static SkXfermode* SkCreate4pxXfermode(const ProcCoeff& rec, SkXfermode::Mode mode) {
+} // namespace
+
+namespace SK_OPTS_NS {
+
+static SkXfermode* create_xfermode(const ProcCoeff& rec, SkXfermode::Mode mode) {
     switch (mode) {
     #define CASE(Mode) case SkXfermode::k##Mode##_Mode: \
         return SkNEW_ARGS(Sk4pxXfermode, (rec, mode, &Mode, &xfer_aa<Mode>))
@@ -314,6 +318,6 @@ static SkXfermode* SkCreate4pxXfermode(const ProcCoeff& rec, SkXfermode::Mode mo
     return nullptr;
 }
 
-} // namespace SK_NS_OPTS
+} // namespace SK_OPTS_NS
 
 #endif//Sk4pxXfermode_DEFINED