Fix all relative includes to third_party.

samples/image_diff_png.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This is a duplicate of chromium's src/tools/imagediff/image_diff_png.cc
 // that has been modified to build in a pdfium environment, which itself
 // was duplicated as follows:
 
 // This is a duplicate of ui/gfx/codec/png_codec.cc, after removing code related
 // to Skia, that we can use when running layout tests with minimal dependencies.
 
 #include "image_diff_png.h"
 
 #include <stdlib.h>
 #include <string.h>
 
 #include <string>
 
-#include "../third_party/base/logging.h"
-#include "../third_party/zlib_v128/zlib.h"
 #include "fx_lpng/include/fx_png.h"
+#include "third_party/base/logging.h"
+#include "third_party/zlib_v128/zlib.h"
 
 namespace image_diff_png {
 
 namespace {
 
 enum ColorFormat {
   // 3 bytes per pixel (packed), in RGB order regardless of endianness.
   // This is the native JPEG format.
   FORMAT_RGB,
 
@@ skipping 603 matching lines @@
                    int height,
                    int row_byte_width,
                    bool discard_transparency,
                    std::vector<unsigned char>* output) {
   return Encode(input, FORMAT_BGRA,
       width, height, row_byte_width, discard_transparency,
       std::vector<Comment>(), output);
 }
 
 }  // image_diff_png