SkPngFilters: guard with libpng >= 1.5.7

src/codec/SkPngCodec.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
 #include "SkColorTable.h"
 #include "SkBitmap.h"
 #include "SkMath.h"
 #include "SkPngCodec.h"
 #include "SkPngFilters.h"
 #include "SkSize.h"
 #include "SkStream.h"
 #include "SkSwizzler.h"
 #include "SkTemplates.h"
 
-#if defined(__SSE2__)
+// png_struct::read_filter[] was added in libpng 1.5.7.
+#if defined(__SSE2__) && PNG_LIBPNG_VER >= 10507
     #include "pngstruct.h"
 
     extern "C" void sk_png_init_filter_functions_sse2(png_structp png, unsigned int bpp) {
         if (bpp == 3) {
             png->read_filter[PNG_FILTER_VALUE_SUB  -1] =   sk_sub3_sse2;
             png->read_filter[PNG_FILTER_VALUE_AVG  -1] =   sk_avg3_sse2;
             png->read_filter[PNG_FILTER_VALUE_PAETH-1] = sk_paeth3_sse2;
         }
         if (bpp == 4) {
             png->read_filter[PNG_FILTER_VALUE_SUB  -1] =   sk_sub4_sse2;
@@ skipping 765 matching lines @@
     }
 
     if (1 == numberPasses) {
         return new SkPngScanlineDecoder(imageInfo, streamDeleter.detach(), chunkReader,
                                         png_ptr, info_ptr, bitDepth);
     }
 
     return new SkPngInterlacedScanlineDecoder(imageInfo, streamDeleter.detach(), chunkReader,
                                               png_ptr, info_ptr, bitDepth, numberPasses);
 }