SkPngFilters: use normal pointer types.

src/codec/SkPngFilters.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkPngFilters_DEFINED
 #define SkPngFilters_DEFINED
 
 #include "png.h"
+#include "SkTypes.h"
 
 // We don't bother specializing Up...
 // it's so simple it's usually already perfectly autovectorized.
 
 // These all require bpp=3 (i.e. RGB).
-void   sk_sub3_sse2(png_row_infop, png_bytep, png_const_bytep);
-void   sk_avg3_sse2(png_row_infop, png_bytep, png_const_bytep);
-void sk_paeth3_sse2(png_row_infop, png_bytep, png_const_bytep);
+void   sk_sub3_sse2(png_row_infop, uint8_t*, const uint8_t*);
+void   sk_avg3_sse2(png_row_infop, uint8_t*, const uint8_t*);
+void sk_paeth3_sse2(png_row_infop, uint8_t*, const uint8_t*);
 
 // These all require bpp=4 (i.e. RGBA).
-void   sk_sub4_sse2(png_row_infop, png_bytep, png_const_bytep);
-void   sk_avg4_sse2(png_row_infop, png_bytep, png_const_bytep);
-void sk_paeth4_sse2(png_row_infop, png_bytep, png_const_bytep);
+void   sk_sub4_sse2(png_row_infop, uint8_t*, const uint8_t*);
+void   sk_avg4_sse2(png_row_infop, uint8_t*, const uint8_t*);
+void sk_paeth4_sse2(png_row_infop, uint8_t*, const uint8_t*);
 
 #endif//SkPngFilterOpts_DEFINED