XFA: Actually fix all relative includes to third_party.

core/src/fxcodec/codec/fx_codec_png.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "../../../include/fxcodec/fx_codec.h"
 #include "../../../include/fxge/fx_dib.h"
 #include "codec_int.h"
+
 extern "C" {
 #undef FAR
-#include "../../../../third_party/lpng_v163/png.h"
+#include "third_party/lpng_v163/png.h"
 }
+
 static void _png_error_data(png_structp png_ptr, png_const_charp error_msg) {
   if (png_get_error_ptr(png_ptr)) {
     FXSYS_strncpy((char*)png_get_error_ptr(png_ptr), error_msg,
                   PNG_ERROR_SIZE - 1);
   }
   longjmp(png_jmpbuf(png_ptr), 1);
 }
 static void _png_warning_data(png_structp png_ptr, png_const_charp error_msg) {}
 static void _png_load_bmp_attribute(png_structp png_ptr,
                                     png_infop info_ptr,
@@ skipping 219 matching lines @@
   if (setjmp(png_jmpbuf(p->png_ptr))) {
     if (pAttribute &&
         0 == FXSYS_strcmp(m_szLastError, "Read Header Callback Error")) {
       _png_load_bmp_attribute(p->png_ptr, p->info_ptr, pAttribute);
     }
     return FALSE;
   }
   png_process_data(p->png_ptr, p->info_ptr, (uint8_t*)src_buf, src_size);
   return TRUE;
 }