Clean up dead xfermode opts code.

src/opts/SkXfermode_opts_none.cpp

Index: src/opts/SkXfermode_opts_none.cpp
diff --git a/src/opts/SkXfermode_opts_none.cpp b/src/opts/SkXfermode_opts_none.cpp
index a2f9b479dd43ce7aec9ff900268730079562353f..832d92eccd52fc6bd2d22d0d4922d03372a9b9eb 100644
--- a/src/opts/SkXfermode_opts_none.cpp
+++ b/src/opts/SkXfermode_opts_none.cpp
@@ -8,17 +8,13 @@
 #include "SkXfermode.h"
 #include "SkXfermode_proccoeff.h"
 
-// The prototypes below are for Clang
-extern SkProcCoeffXfermode* SkPlatformXfermodeFactory(const ProcCoeff& rec,
-                                                      SkXfermode::Mode mode);
 
-extern SkXfermodeProc SkPlatformXfermodeProcFactory(SkXfermode::Mode mode);
-
-SkProcCoeffXfermode* SkPlatformXfermodeFactory(const ProcCoeff& rec,
-                                               SkXfermode::Mode mode) {
+SkProcCoeffXfermode* SkPlatformXfermodeFactory(const ProcCoeff& rec, SkXfermode::Mode mode);
+SkProcCoeffXfermode* SkPlatformXfermodeFactory(const ProcCoeff& rec, SkXfermode::Mode mode) {
     return NULL;
 }
 
+SkXfermodeProc SkPlatformXfermodeProcFactory(SkXfermode::Mode mode);
 SkXfermodeProc SkPlatformXfermodeProcFactory(SkXfermode::Mode mode) {
     return NULL;
 }