More win64 warning fixes

src/core/SkDistanceFieldGen.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkDistanceFieldGen_DEFINED
 #define SkDistanceFieldGen_DEFINED
 
 #include "SkTypes.h"
@@ skipping 17 matching lines @@
 
  *  @param distanceField     The distance field to be generated. Should already be allocated
  *                           by the client with the padding above.
  *  @param image             8-bit mask we're using to generate the distance field.
  *  @param w                 Width of the original image.
  *  @param h                 Height of the original image.
  *  @param rowBytes          Size of each row in the image, in bytes
  */
 bool SkGenerateDistanceFieldFromA8Image(unsigned char* distanceField,
                                         const unsigned char* image,
-                                        int w, int h, int rowBytes);
+                                        int w, int h, size_t rowBytes);
 
 /** Given 1-bit mask data, generate the associated distance field
 
  *  @param distanceField     The distance field to be generated. Should already be allocated
  *                           by the client with the padding above.
  *  @param image             1-bit mask we're using to generate the distance field.
  *  @param w                 Width of the original image.
  *  @param h                 Height of the original image.
  *  @param rowBytes          Size of each row in the image, in bytes
  */
 bool SkGenerateDistanceFieldFromBWImage(unsigned char* distanceField,
                                         const unsigned char* image,
-                                        int w, int h, int rowBytes);
+                                        int w, int h, size_t rowBytes);
 
 /** Given width and height of original image, return size (in bytes) of distance field
  *  @param w                 Width of the original image.
  *  @param h                 Height of the original image.
  */
 inline size_t SkComputeDistanceFieldSize(int w, int h) {
     return (w + 2*SK_DistanceFieldPad) * (h + 2*SK_DistanceFieldPad) * sizeof(unsigned char);
 }
 
 #endif