spriteblitter for memcpy case (for all configs)

include/core/SkPixmap.h

Index: include/core/SkPixmap.h
diff --git a/include/core/SkPixmap.h b/include/core/SkPixmap.h
index 5f90273a97dacfba6217e820217546c78d8b73a8..c3c27bec78ac4bece736520749a612e3204b12ab 100644
--- a/include/core/SkPixmap.h
+++ b/include/core/SkPixmap.h
@@ -80,7 +80,7 @@ public:
      *  Return the shift amount per pixel (i.e. 0 for 1-byte per pixel, 1 for 2-bytes per pixel
      *  colortypes, 2 for 4-bytes per pixel colortypes). Return 0 for kUnknown_SkColorType.
      */
-    int shiftPerPixel() const { return fInfo.bytesPerPixel() >> 1; }
+    int shiftPerPixel() const { return fInfo.shiftPerPixel(); }
 
     uint64_t getSize64() const { return sk_64_mul(fInfo.height(), fRowBytes); }
     uint64_t getSafeSize64() const { return fInfo.getSafeSize64(fRowBytes); }
@@ -141,6 +141,9 @@ public:
     // Writable versions
 
     void* writable_addr() const { return const_cast<void*>(fPixels); }
+    void* writable_addr(int x, int y) const {
+        return const_cast<void*>(this->addr(x, y));
+    }
     uint8_t* writable_addr8(int x, int y) const {
         return const_cast<uint8_t*>(this->addr8(x, y));
     }