Revert of 565 support for SIMD xfermodes

src/core/Sk4pxXfermode.h

Index: src/core/Sk4pxXfermode.h
diff --git a/src/core/Sk4pxXfermode.h b/src/core/Sk4pxXfermode.h
index ad822edb8b609f32d7db0e29e0e7ef796258af1e..fc0b643be1454de4893fc8f9c1caa8311eef4abd 100644
--- a/src/core/Sk4pxXfermode.h
+++ b/src/core/Sk4pxXfermode.h
@@ -222,19 +222,6 @@
         }
     }
 
-    void xfer16(uint16_t dst[], const SkPMColor src[], int n, const SkAlpha aa[]) const override {
-        if (NULL == aa) {
-            Sk4px::MapDstSrc(n, dst, src, [&](const Sk4px& dst4, const Sk4px& src4) {
-                return fProc4(src4, dst4);
-            });
-        } else {
-            Sk4px::MapDstSrcAlpha(n, dst, src, aa,
-                    [&](const Sk4px& dst4, const Sk4px& src4, const Sk4px& alpha) {
-                return fAAProc4(src4, dst4, alpha);
-            });
-        }
-    }
-
 private:
     Proc4 fProc4;
     AAProc4 fAAProc4;
@@ -250,35 +237,19 @@
 
     void xfer32(SkPMColor dst[], const SkPMColor src[], int n, const SkAlpha aa[]) const override {
         for (int i = 0; i < n; i++) {
-            dst[i] = aa ? this->xfer32(dst[i], src[i], aa[i])
-                        : this->xfer32(dst[i], src[i]);
+            SkPMFloat s(src[i]),
+                      d(dst[i]),
+                      b(fProcF(s,d));
+            if (aa) {
+                // We do aa in full float precision before going back down to bytes, because we can!
+                SkPMFloat a = Sk4f(aa[i]) * Sk4f(1.0f/255);
+                b = b*a + d*(Sk4f(1)-a);
+            }
+            dst[i] = b.round();
         }
     }
 
-    void xfer16(uint16_t dst[], const SkPMColor src[], int n, const SkAlpha aa[]) const override {
-        for (int i = 0; i < n; i++) {
-            SkPMColor dst32 = SkPixel16ToPixel32(dst[i]);
-            dst32 = aa ? this->xfer32(dst32, src[i], aa[i])
-                       : this->xfer32(dst32, src[i]);
-            dst[i] = SkPixel32ToPixel16(dst32);
-        }
-    }
-
 private:
-    inline SkPMColor xfer32(SkPMColor dst, SkPMColor src) const {
-        return fProcF(SkPMFloat(src), SkPMFloat(dst)).round();
-    }
-
-    inline SkPMColor xfer32(SkPMColor dst, SkPMColor src, SkAlpha aa) const {
-        SkPMFloat s(src),
-                  d(dst),
-                  b(fProcF(s,d));
-        // We do aa in full float precision before going back down to bytes, because we can!
-        SkPMFloat a = Sk4f(aa) * Sk4f(1.0f/255);
-        b = b*a + d*(Sk4f(1)-a);
-        return b.round();
-    }
-
     ProcF fProcF;
     typedef SkProcCoeffXfermode INHERITED;
 };