Port SkXfermode opts to SkOpts.h

src/opts/SkOpts_neon.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
+#include "SkFloatingPoint.h"
 #include "SkOpts.h"
-#include "SkFloatingPoint.h"
+#include "SkXfermode_opts.h"
 
 namespace neon {  // This helps identify methods from this file when debugging / profiling.
 
 static float rsqrt(float x) {
     return sk_float_rsqrt(x);  // This sk_float_rsqrt copy will take the NEON compile-time path.
 }
 
 static void memset16(uint16_t* dst, uint16_t value, int n) {
     uint16x8_t   v8  = vdupq_n_u16(value);
     uint16x8x4_t v32 = {{ v8, v8, v8, v8 }};
@@ skipping 39 matching lines @@
     }
     if (n & 1) {
         *dst = value;
     }
 }
 
 }  // namespace neon
 
 namespace SkOpts {
     void Init_neon() {
-        rsqrt    = neon::rsqrt;
-        memset16 = neon::memset16;
-        memset32 = neon::memset32;
+        rsqrt           = neon::rsqrt;
+        memset16        = neon::memset16;
+        memset32        = neon::memset32;
+        create_xfermode = SkCreate4pxXfermode;
     }
 }