Move image_diff code into testing/image_diff/

It is not actually a sample program to demonstrate how to use PDFium
APIs. It is more of a test utility program.

Remove header include dependency from samples/ to core/, to set a good
example.

Change-Id: Idd5d567c82314bcf0e4a7bec8a3210e7d57226ee
Reviewed-on: https://pdfium-review.googlesource.com/6871
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

1 files changed, 0 insertions, 38 deletions

diff --git a/samples/image_diff_png.h b/samples/image_diff_png.h
deleted file mode 100644
index 7bb395a4a5..0000000000
--- a/samples/image_diff_png.h
+++ /dev/null
@@ -1,38 +0,0 @@
-// 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.
-
-#ifndef SAMPLES_IMAGE_DIFF_PNG_H_
-#define SAMPLES_IMAGE_DIFF_PNG_H_
-
-#include <stdlib.h>  // for size_t.
-
-#include <vector>
-
-namespace image_diff_png {
-
-// Decode a PNG into an RGBA pixel array.
-bool DecodePNG(const unsigned char* input,
-               size_t input_size,
-               std::vector<unsigned char>* output,
-               int* width,
-               int* height);
-
-// Encode an RGBA pixel array into a PNG.
-bool EncodeRGBAPNG(const unsigned char* input,
-                   int width,
-                   int height,
-                   int row_byte_width,
-                   std::vector<unsigned char>* output);
-
-// Encode an BGRA pixel array into a PNG.
-bool EncodeBGRAPNG(const unsigned char* input,
-                   int width,
-                   int height,
-                   int row_byte_width,
-                   bool discard_transparency,
-                   std::vector<unsigned char>* output);
-
-}  // namespace image_diff_png
-
-#endif  // SAMPLES_IMAGE_DIFF_PNG_H_