Backport PNG output format to origin/master branch.

The pdfium library itself does not support the format, but the test utility
can convert to this output format.

GN build can't be tested standalone, so push this out to the next CL.

R=jam@chromium.org

Review URL: https://codereview.chromium.org/950113002

1 files changed, 36 insertions, 0 deletions

diff --git a/samples/image_diff_png.h b/samples/image_diff_png.h
new file mode 100644
index 0000000000..9febb3744c
--- /dev/null
+++ b/samples/image_diff_png.h
@@ -0,0 +1,36 @@
+// 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 TOOLS_IMAGEDIFF_IMAGE_DIFF_PNG_H_
+#define TOOLS_IMAGEDIFF_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  // TOOLS_IMAGEDIFF_IMAGE_DIFF_PNG_H_