Even more win64 warning fixes

src/utils/SkTextureCompressor_ASTC.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 SkTextureCompressor_ASTC_DEFINED
 #define SkTextureCompressor_ASTC_DEFINED
 
 #include "SkBitmapProcShader.h"
 
 class SkBlitter;
 
 namespace SkTextureCompressor {
 
     bool CompressA8To12x12ASTC(uint8_t* dst, const uint8_t* src,
-                               int width, int height, int rowBytes);
+                               int width, int height, size_t rowBytes);
 
     SkBlitter* CreateASTCBlitter(int width, int height, void* outputBuffer,
                                  SkTBlitterAllocator *allocator);
 
     void DecompressASTC(uint8_t* dst, int dstRowBytes, const uint8_t* src,
                         int width, int height, int blockDimX, int blockDimY);
 }
 
 #endif  // SkTextureCompressor_ASTC_DEFINED