Move image codec stuff to toplevel gfx.

TBR=darin
BUG=none
TEST=none


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@41911 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 1841 insertions, 0 deletions

diff --git a/gfx/codec/DEPS b/gfx/codec/DEPS
new file mode 100644
index 0000000..e4907a6c
--- /dev/null
+++ b/gfx/codec/DEPS
@@ -0,0 +1,5 @@
+include_rules = [
+  "+skia",
+  "+third_party/libjpeg",
+  "+third_party/libpng",
+]
diff --git a/gfx/codec/jpeg_codec.cc b/gfx/codec/jpeg_codec.cc
new file mode 100644
index 0000000..d16a6d2b
--- /dev/null
+++ b/gfx/codec/jpeg_codec.cc
@@ -0,0 +1,531 @@
+// Copyright (c) 2006-2008 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.
+
+#include "gfx/codec/jpeg_codec.h"
+
+#include <setjmp.h>
+
+#include "base/logging.h"
+#include "base/scoped_ptr.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+
+extern "C" {
+#if defined(USE_SYSTEM_LIBJPEG)
+#include <jpeglib.h>
+#else
+#include "third_party/libjpeg/jpeglib.h"
+#endif
+}
+
+namespace gfx {
+
+// Encoder/decoder shared stuff ------------------------------------------------
+
+namespace {
+
+// used to pass error info through the JPEG library
+struct CoderErrorMgr {
+  jpeg_error_mgr pub;
+  jmp_buf setjmp_buffer;
+};
+
+void ErrorExit(jpeg_common_struct* cinfo) {
+  CoderErrorMgr *err = reinterpret_cast<CoderErrorMgr*>(cinfo->err);
+
+  // Return control to the setjmp point.
+  longjmp(err->setjmp_buffer, false);
+}
+
+}  // namespace
+
+// Encoder ---------------------------------------------------------------------
+//
+// This code is based on nsJPEGEncoder from Mozilla.
+// Copyright 2005 Google Inc. (Brett Wilson, contributor)
+
+namespace {
+
+// Initial size for the output buffer in the JpegEncoderState below.
+static const int initial_output_buffer_size = 8192;
+
+struct JpegEncoderState {
+  explicit JpegEncoderState(std::vector<unsigned char>* o)
+      : out(o),
+        image_buffer_used(0) {
+  }
+
+  // Output buffer, of which 'image_buffer_used' bytes are actually used (this
+  // will often be less than the actual size of the vector because we size it
+  // so that libjpeg can write directly into it.
+  std::vector<unsigned char>* out;
+
+  // Number of bytes in the 'out' buffer that are actually used (see above).
+  size_t image_buffer_used;
+};
+
+// Initializes the JpegEncoderState for encoding, and tells libjpeg about where
+// the output buffer is.
+//
+// From the JPEG library:
+//  "Initialize destination. This is called by jpeg_start_compress() before
+//   any data is actually written. It must initialize next_output_byte and
+//   free_in_buffer. free_in_buffer must be initialized to a positive value."
+void InitDestination(jpeg_compress_struct* cinfo) {
+  JpegEncoderState* state = static_cast<JpegEncoderState*>(cinfo->client_data);
+  DCHECK(state->image_buffer_used == 0) << "initializing after use";
+
+  state->out->resize(initial_output_buffer_size);
+  state->image_buffer_used = 0;
+
+  cinfo->dest->next_output_byte = &(*state->out)[0];
+  cinfo->dest->free_in_buffer = initial_output_buffer_size;
+}
+
+// Resize the buffer that we give to libjpeg and update our and its state.
+//
+// From the JPEG library:
+//  "Callback used by libjpeg whenever the buffer has filled (free_in_buffer
+//   reaches zero). In typical applications, it should write out the *entire*
+//   buffer (use the saved start address and buffer length; ignore the current
+//   state of next_output_byte and free_in_buffer). Then reset the pointer &
+//   count to the start of the buffer, and return TRUE indicating that the
+//   buffer has been dumped. free_in_buffer must be set to a positive value
+//   when TRUE is returned. A FALSE return should only be used when I/O
+//   suspension is desired (this operating mode is discussed in the next
+//   section)."
+boolean EmptyOutputBuffer(jpeg_compress_struct* cinfo) {
+  JpegEncoderState* state = static_cast<JpegEncoderState*>(cinfo->client_data);
+
+  // note the new size, the buffer is full
+  state->image_buffer_used = state->out->size();
+
+  // expand buffer, just double size each time
+  state->out->resize(state->out->size() * 2);
+
+  // tell libjpeg where to write the next data
+  cinfo->dest->next_output_byte = &(*state->out)[state->image_buffer_used];
+  cinfo->dest->free_in_buffer = state->out->size() - state->image_buffer_used;
+  return 1;
+}
+
+// Cleans up the JpegEncoderState to prepare for returning in the final form.
+//
+// From the JPEG library:
+//  "Terminate destination --- called by jpeg_finish_compress() after all data
+//   has been written. In most applications, this must flush any data
+//   remaining in the buffer. Use either next_output_byte or free_in_buffer to
+//   determine how much data is in the buffer."
+void TermDestination(jpeg_compress_struct* cinfo) {
+  JpegEncoderState* state = static_cast<JpegEncoderState*>(cinfo->client_data);
+  DCHECK(state->out->size() >= state->image_buffer_used);
+
+  // update the used byte based on the next byte libjpeg would write to
+  state->image_buffer_used = cinfo->dest->next_output_byte - &(*state->out)[0];
+  DCHECK(state->image_buffer_used < state->out->size()) <<
+    "JPEG library busted, got a bad image buffer size";
+
+  // update our buffer so that it exactly encompases the desired data
+  state->out->resize(state->image_buffer_used);
+}
+
+// Converts RGBA to RGB (removing the alpha values) to prepare to send data to
+// libjpeg. This converts one row of data in rgba with the given width in
+// pixels the the given rgb destination buffer (which should have enough space
+// reserved for the final data).
+void StripAlpha(const unsigned char* rgba, int pixel_width, unsigned char* rgb)
+{
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &rgba[x * 4];
+    unsigned char* pixel_out = &rgb[x * 3];
+    pixel_out[0] = pixel_in[0];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[2];
+  }
+}
+
+// Converts BGRA to RGB by reordering the color components and dropping the
+// alpha. This converts  one row of data in rgba with the given width in
+// pixels the the given rgb destination buffer (which should have enough space
+// reserved for the final data).
+void BGRAtoRGB(const unsigned char* bgra, int pixel_width, unsigned char* rgb)
+{
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &bgra[x * 4];
+    unsigned char* pixel_out = &rgb[x * 3];
+    pixel_out[0] = pixel_in[2];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[0];
+  }
+}
+
+// This class destroys the given jpeg_compress object when it goes out of
+// scope. It simplifies the error handling in Encode (and even applies to the
+// success case).
+class CompressDestroyer {
+ public:
+  CompressDestroyer() : cinfo_(NULL) {
+  }
+  ~CompressDestroyer() {
+    DestroyManagedObject();
+  }
+  void SetManagedObject(jpeg_compress_struct* ci) {
+    DestroyManagedObject();
+    cinfo_ = ci;
+  }
+  void DestroyManagedObject() {
+    if (cinfo_) {
+      jpeg_destroy_compress(cinfo_);
+      cinfo_ = NULL;
+    }
+  }
+ private:
+  jpeg_compress_struct* cinfo_;
+};
+
+}  // namespace
+
+bool JPEGCodec::Encode(const unsigned char* input, ColorFormat format,
+                       int w, int h, int row_byte_width,
+                       int quality, std::vector<unsigned char>* output) {
+  jpeg_compress_struct cinfo;
+  CompressDestroyer destroyer;
+  destroyer.SetManagedObject(&cinfo);
+  output->clear();
+
+  // We set up the normal JPEG error routines, then override error_exit.
+  // This must be done before the call to create_compress.
+  CoderErrorMgr errmgr;
+  cinfo.err = jpeg_std_error(&errmgr.pub);
+  errmgr.pub.error_exit = ErrorExit;
+  // Establish the setjmp return context for ErrorExit to use.
+  if (setjmp(errmgr.setjmp_buffer)) {
+    // If we get here, the JPEG code has signaled an error.
+    // MSDN notes: "if you intend your code to be portable, do not rely on
+    // correct destruction of frame-based objects when executing a nonlocal
+    // goto using a call to longjmp."  So we delete the CompressDestroyer's
+    // object manually instead.
+    destroyer.DestroyManagedObject();
+    return false;
+  }
+
+  // The destroyer will destroy() cinfo on exit.
+  jpeg_create_compress(&cinfo);
+
+  cinfo.image_width = w;
+  cinfo.image_height = h;
+  cinfo.input_components = 3;
+  cinfo.in_color_space = JCS_RGB;
+  cinfo.data_precision = 8;
+
+  jpeg_set_defaults(&cinfo);
+  jpeg_set_quality(&cinfo, quality, 1);  // quality here is 0-100
+
+  // set up the destination manager
+  jpeg_destination_mgr destmgr;
+  destmgr.init_destination = InitDestination;
+  destmgr.empty_output_buffer = EmptyOutputBuffer;
+  destmgr.term_destination = TermDestination;
+  cinfo.dest = &destmgr;
+
+  JpegEncoderState state(output);
+  cinfo.client_data = &state;
+
+  jpeg_start_compress(&cinfo, 1);
+
+  // feed it the rows, doing necessary conversions for the color format
+  if (format == FORMAT_RGB) {
+    // no conversion necessary
+    while (cinfo.next_scanline < cinfo.image_height) {
+      const unsigned char* row = &input[cinfo.next_scanline * row_byte_width];
+      jpeg_write_scanlines(&cinfo, const_cast<unsigned char**>(&row), 1);
+    }
+  } else {
+    // get the correct format converter
+    void (*converter)(const unsigned char* in, int w, unsigned char* rgb);
+    if (format == FORMAT_RGBA) {
+      converter = StripAlpha;
+    } else if (format == FORMAT_BGRA) {
+      converter = BGRAtoRGB;
+    } else {
+      NOTREACHED() << "Invalid pixel format";
+      return false;
+    }
+
+    // output row after converting
+    unsigned char* row = new unsigned char[w * 3];
+
+    while (cinfo.next_scanline < cinfo.image_height) {
+      converter(&input[cinfo.next_scanline * row_byte_width], w, row);
+      jpeg_write_scanlines(&cinfo, &row, 1);
+    }
+    delete[] row;
+  }
+
+  jpeg_finish_compress(&cinfo);
+  return true;
+}
+
+// Decoder --------------------------------------------------------------------
+
+namespace {
+
+struct JpegDecoderState {
+  JpegDecoderState(const unsigned char* in, size_t len)
+      : input_buffer(in), input_buffer_length(len) {
+  }
+
+  const unsigned char* input_buffer;
+  size_t input_buffer_length;
+};
+
+// Callback to initialize the source.
+//
+// From the JPEG library:
+//  "Initialize source. This is called by jpeg_read_header() before any data is
+//   actually read. May leave bytes_in_buffer set to 0 (in which case a
+//   fill_input_buffer() call will occur immediately)."
+void InitSource(j_decompress_ptr cinfo) {
+  JpegDecoderState* state = static_cast<JpegDecoderState*>(cinfo->client_data);
+  cinfo->src->next_input_byte = state->input_buffer;
+  cinfo->src->bytes_in_buffer = state->input_buffer_length;
+}
+
+// Callback to fill the buffer. Since our buffer already contains all the data,
+// we should never need to provide more data. If libjpeg thinks it needs more
+// data, our input is probably corrupt.
+//
+// From the JPEG library:
+//  "This is called whenever bytes_in_buffer has reached zero and more data is
+//   wanted. In typical applications, it should read fresh data into the buffer
+//   (ignoring the current state of next_input_byte and bytes_in_buffer), reset
+//   the pointer & count to the start of the buffer, and return TRUE indicating
+//   that the buffer has been reloaded. It is not necessary to fill the buffer
+//   entirely, only to obtain at least one more byte. bytes_in_buffer MUST be
+//   set to a positive value if TRUE is returned. A FALSE return should only
+//   be used when I/O suspension is desired."
+boolean FillInputBuffer(j_decompress_ptr cinfo) {
+  return false;
+}
+
+// Skip data in the buffer. Since we have all the data at once, this operation
+// is easy. It is not clear if this ever gets called because the JPEG library
+// should be able to do the skip itself (it has all the data).
+//
+// From the JPEG library:
+//  "Skip num_bytes worth of data. The buffer pointer and count should be
+//   advanced over num_bytes input bytes, refilling the buffer as needed. This
+//   is used to skip over a potentially large amount of uninteresting data
+//   (such as an APPn marker). In some applications it may be possible to
+//   optimize away the reading of the skipped data, but it's not clear that
+//   being smart is worth much trouble; large skips are uncommon.
+//   bytes_in_buffer may be zero on return. A zero or negative skip count
+//   should be treated as a no-op."
+void SkipInputData(j_decompress_ptr cinfo, long num_bytes) {
+  if (num_bytes > static_cast<long>(cinfo->src->bytes_in_buffer)) {
+    // Since all our data should be in the buffer, trying to skip beyond it
+    // means that there is some kind of error or corrupt input data. A 0 for
+    // bytes left means it will call FillInputBuffer which will then fail.
+    cinfo->src->next_input_byte += cinfo->src->bytes_in_buffer;
+    cinfo->src->bytes_in_buffer = 0;
+  } else if (num_bytes > 0) {
+    cinfo->src->bytes_in_buffer -= static_cast<size_t>(num_bytes);
+    cinfo->src->next_input_byte += num_bytes;
+  }
+}
+
+// Our source doesn't need any cleanup, so this is a NOP.
+//
+// From the JPEG library:
+//  "Terminate source --- called by jpeg_finish_decompress() after all data has
+//   been read to clean up JPEG source manager. NOT called by jpeg_abort() or
+//   jpeg_destroy()."
+void TermSource(j_decompress_ptr cinfo) {
+}
+
+// Converts one row of rgb data to rgba data by adding a fully-opaque alpha
+// value.
+void AddAlpha(const unsigned char* rgb, int pixel_width, unsigned char* rgba) {
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &rgb[x * 3];
+    unsigned char* pixel_out = &rgba[x * 4];
+    pixel_out[0] = pixel_in[0];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[2];
+    pixel_out[3] = 0xff;
+  }
+}
+
+// Converts one row of RGB data to BGRA by reordering the color components and
+// adding alpha values of 0xff.
+void RGBtoBGRA(const unsigned char* bgra, int pixel_width, unsigned char* rgb)
+{
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &bgra[x * 3];
+    unsigned char* pixel_out = &rgb[x * 4];
+    pixel_out[0] = pixel_in[2];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[0];
+    pixel_out[3] = 0xff;
+  }
+}
+
+// This class destroys the given jpeg_decompress object when it goes out of
+// scope. It simplifies the error handling in Decode (and even applies to the
+// success case).
+class DecompressDestroyer {
+ public:
+  DecompressDestroyer() : cinfo_(NULL) {
+  }
+  ~DecompressDestroyer() {
+    DestroyManagedObject();
+  }
+  void SetManagedObject(jpeg_decompress_struct* ci) {
+    DestroyManagedObject();
+    cinfo_ = ci;
+  }
+  void DestroyManagedObject() {
+    if (cinfo_) {
+      jpeg_destroy_decompress(cinfo_);
+      cinfo_ = NULL;
+    }
+  }
+ private:
+  jpeg_decompress_struct* cinfo_;
+};
+
+}  // namespace
+
+bool JPEGCodec::Decode(const unsigned char* input, size_t input_size,
+                       ColorFormat format, std::vector<unsigned char>* output,
+                       int* w, int* h) {
+  jpeg_decompress_struct cinfo;
+  DecompressDestroyer destroyer;
+  destroyer.SetManagedObject(&cinfo);
+  output->clear();
+
+  // We set up the normal JPEG error routines, then override error_exit.
+  // This must be done before the call to create_decompress.
+  CoderErrorMgr errmgr;
+  cinfo.err = jpeg_std_error(&errmgr.pub);
+  errmgr.pub.error_exit = ErrorExit;
+  // Establish the setjmp return context for ErrorExit to use.
+  if (setjmp(errmgr.setjmp_buffer)) {
+    // If we get here, the JPEG code has signaled an error.
+    // See note in JPEGCodec::Encode() for why we need to destroy the cinfo
+    // manually here.
+    destroyer.DestroyManagedObject();
+    return false;
+  }
+
+  // The destroyer will destroy() cinfo on exit.  We don't want to set the
+  // destroyer's object until cinfo is initialized.
+  jpeg_create_decompress(&cinfo);
+
+  // set up the source manager
+  jpeg_source_mgr srcmgr;
+  srcmgr.init_source = InitSource;
+  srcmgr.fill_input_buffer = FillInputBuffer;
+  srcmgr.skip_input_data = SkipInputData;
+  srcmgr.resync_to_restart = jpeg_resync_to_restart;  // use default routine
+  srcmgr.term_source = TermSource;
+  cinfo.src = &srcmgr;
+
+  JpegDecoderState state(input, input_size);
+  cinfo.client_data = &state;
+
+  // fill the file metadata into our buffer
+  if (jpeg_read_header(&cinfo, true) != JPEG_HEADER_OK)
+    return false;
+
+  // we want to always get RGB data out
+  switch (cinfo.jpeg_color_space) {
+    case JCS_GRAYSCALE:
+    case JCS_RGB:
+    case JCS_YCbCr:
+      cinfo.out_color_space = JCS_RGB;
+      break;
+    case JCS_CMYK:
+    case JCS_YCCK:
+    default:
+      // Mozilla errors out on these color spaces, so I presume that the jpeg
+      // library can't do automatic color space conversion for them. We don't
+      // care about these anyway.
+      return false;
+  }
+  cinfo.output_components = 3;
+
+  jpeg_calc_output_dimensions(&cinfo);
+  *w = cinfo.output_width;
+  *h = cinfo.output_height;
+
+  jpeg_start_decompress(&cinfo);
+
+  // FIXME(brettw) we may want to allow the capability for callers to request
+  // how to align row lengths as we do for the compressor.
+  int row_read_stride = cinfo.output_width * cinfo.output_components;
+
+  if (format == FORMAT_RGB) {
+    // easy case, row needs no conversion
+    int row_write_stride = row_read_stride;
+    output->resize(row_write_stride * cinfo.output_height);
+
+    for (int row = 0; row < static_cast<int>(cinfo.output_height); row++) {
+      unsigned char* rowptr = &(*output)[row * row_write_stride];
+      if (!jpeg_read_scanlines(&cinfo, &rowptr, 1))
+        return false;
+    }
+  } else {
+    // Rows need conversion to output format: read into a temporary buffer and
+    // expand to the final one. Performance: we could avoid the extra
+    // allocation by doing the expansion in-place.
+    int row_write_stride;
+    void (*converter)(const unsigned char* rgb, int w, unsigned char* out);
+    if (format == FORMAT_RGBA) {
+      row_write_stride = cinfo.output_width * 4;
+      converter = AddAlpha;
+    } else if (format == FORMAT_BGRA) {
+      row_write_stride = cinfo.output_width * 4;
+      converter = RGBtoBGRA;
+    } else {
+      NOTREACHED() << "Invalid pixel format";
+      jpeg_destroy_decompress(&cinfo);
+      return false;
+    }
+
+    output->resize(row_write_stride * cinfo.output_height);
+
+    scoped_array<unsigned char> row_data(new unsigned char[row_read_stride]);
+    unsigned char* rowptr = row_data.get();
+    for (int row = 0; row < static_cast<int>(cinfo.output_height); row++) {
+      if (!jpeg_read_scanlines(&cinfo, &rowptr, 1))
+        return false;
+      converter(rowptr, *w, &(*output)[row * row_write_stride]);
+    }
+  }
+
+  jpeg_finish_decompress(&cinfo);
+  jpeg_destroy_decompress(&cinfo);
+  return true;
+}
+
+// static
+SkBitmap* JPEGCodec::Decode(const unsigned char* input, size_t input_size) {
+  int w, h;
+  std::vector<unsigned char> data_vector;
+  // Use FORMAT_BGRA as that maps to Skia's 32 bit (kARGB_8888_Config) format.
+  if (!Decode(input, input_size, FORMAT_BGRA, &data_vector, &w, &h))
+    return NULL;
+
+  // Skia only handles 32 bit images.
+  int data_length = w * h * 4;
+
+  SkBitmap* bitmap = new SkBitmap();
+  bitmap->setConfig(SkBitmap::kARGB_8888_Config, w, h);
+  bitmap->allocPixels();
+  memcpy(bitmap->getAddr32(0, 0), &data_vector[0], data_length);
+
+  return bitmap;
+}
+
+}  // namespace gfx
diff --git a/gfx/codec/jpeg_codec.h b/gfx/codec/jpeg_codec.h
new file mode 100644
index 0000000..792930f
--- /dev/null
+++ b/gfx/codec/jpeg_codec.h
@@ -0,0 +1,63 @@
+// Copyright (c) 2009 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 GFX_CODEC_JPEG_CODEC_H_
+#define GFX_CODEC_JPEG_CODEC_H_
+
+#include <vector>
+
+class SkBitmap;
+
+namespace gfx {
+
+// Interface for encoding/decoding JPEG data. This is a wrapper around libjpeg,
+// which has an inconvenient interface for callers. This is only used for UI
+// elements, WebKit has its own more complicated JPEG decoder which handles,
+// among other things, partially downloaded data.
+class JPEGCodec {
+ public:
+  enum ColorFormat {
+    // 3 bytes per pixel (packed), in RGB order regardless of endianness.
+    // This is the native JPEG format.
+    FORMAT_RGB,
+
+    // 4 bytes per pixel, in RGBA order in mem regardless of endianness.
+    FORMAT_RGBA,
+
+    // 4 bytes per pixel, in BGRA order in mem regardless of endianness.
+    // This is the default Windows DIB order.
+    FORMAT_BGRA
+  };
+
+  // Encodes the given raw 'input' data, with each pixel being represented as
+  // given in 'format'. The encoded JPEG data will be written into the supplied
+  // vector and true will be returned on success. On failure (false), the
+  // contents of the output buffer are undefined.
+  //
+  // w, h: dimensions of the image
+  // row_byte_width: the width in bytes of each row. This may be greater than
+  //   w * bytes_per_pixel if there is extra padding at the end of each row
+  //   (often, each row is padded to the next machine word).
+  // quality: an integer in the range 0-100, where 100 is the highest quality.
+  static bool Encode(const unsigned char* input, ColorFormat format,
+                     int w, int h, int row_byte_width,
+                     int quality, std::vector<unsigned char>* output);
+
+  // Decodes the JPEG data contained in input of length input_size. The
+  // decoded data will be placed in *output with the dimensions in *w and *h
+  // on success (returns true). This data will be written in the'format'
+  // format. On failure, the values of these output variables is undefined.
+  static bool Decode(const unsigned char* input, size_t input_size,
+                     ColorFormat format, std::vector<unsigned char>* output,
+                     int* w, int* h);
+
+  // Decodes the JPEG data contained in input of length input_size. If
+  // successful, a SkBitmap is created and returned. It is up to the caller
+  // to delete the returned bitmap.
+  static SkBitmap* Decode(const unsigned char* input, size_t input_size);
+};
+
+}  // namespace gfx
+
+#endif  // GFX_CODEC_JPEG_CODEC_H_
diff --git a/gfx/codec/jpeg_codec_unittest.cc b/gfx/codec/jpeg_codec_unittest.cc
new file mode 100644
index 0000000..16fc848
--- /dev/null
+++ b/gfx/codec/jpeg_codec_unittest.cc
@@ -0,0 +1,151 @@
+// Copyright (c) 2009 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.
+
+#include <math.h>
+
+#include "gfx/codec/jpeg_codec.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace gfx {
+
+// out of 100, this indicates how compressed it will be, this should be changed
+// with jpeg equality threshold
+// static int jpeg_quality = 75;  // FIXME(brettw)
+static int jpeg_quality = 100;
+
+// The threshold of average color differences where we consider two images
+// equal. This number was picked to be a little above the observed difference
+// using the above quality.
+static double jpeg_equality_threshold = 1.0;
+
+// Computes the average difference between each value in a and b. A and b
+// should be the same size. Used to see if two images are approximately equal
+// in the presence of compression.
+static double AveragePixelDelta(const std::vector<unsigned char>& a,
+                                const std::vector<unsigned char>& b) {
+  // if the sizes are different, say the average difference is the maximum
+  if (a.size() != b.size())
+    return 255.0;
+  if (a.size() == 0)
+    return 0;  // prevent divide by 0 below
+
+  double acc = 0.0;
+  for (size_t i = 0; i < a.size(); i++)
+    acc += fabs(static_cast<double>(a[i]) - static_cast<double>(b[i]));
+
+  return acc / static_cast<double>(a.size());
+}
+
+static void MakeRGBImage(int w, int h, std::vector<unsigned char>* dat) {
+  dat->resize(w * h * 3);
+  for (int y = 0; y < h; y++) {
+    for (int x = 0; x < w; x++) {
+      unsigned char* org_px = &(*dat)[(y * w + x) * 3];
+      org_px[0] = x * 3;      // r
+      org_px[1] = x * 3 + 1;  // g
+      org_px[2] = x * 3 + 2;  // b
+    }
+  }
+}
+
+TEST(JPEGCodec, EncodeDecodeRGB) {
+  int w = 20, h = 20;
+
+  // create an image with known values
+  std::vector<unsigned char> original;
+  MakeRGBImage(w, h, &original);
+
+  // encode, making sure it was compressed some
+  std::vector<unsigned char> encoded;
+  EXPECT_TRUE(JPEGCodec::Encode(&original[0], JPEGCodec::FORMAT_RGB, w, h,
+                                w * 3, jpeg_quality, &encoded));
+  EXPECT_GT(original.size(), encoded.size());
+
+  // decode, it should have the same size as the original
+  std::vector<unsigned char> decoded;
+  int outw, outh;
+  EXPECT_TRUE(JPEGCodec::Decode(&encoded[0], encoded.size(),
+                                JPEGCodec::FORMAT_RGB, &decoded,
+                                &outw, &outh));
+  ASSERT_EQ(w, outw);
+  ASSERT_EQ(h, outh);
+  ASSERT_EQ(original.size(), decoded.size());
+
+  // Images must be approximately equal (compression will have introduced some
+  // minor artifacts).
+  ASSERT_GE(jpeg_equality_threshold, AveragePixelDelta(original, decoded));
+}
+
+TEST(JPEGCodec, EncodeDecodeRGBA) {
+  int w = 20, h = 20;
+
+  // create an image with known values, a must be opaque because it will be
+  // lost during compression
+  std::vector<unsigned char> original;
+  original.resize(w * h * 4);
+  for (int y = 0; y < h; y++) {
+    for (int x = 0; x < w; x++) {
+      unsigned char* org_px = &original[(y * w + x) * 4];
+      org_px[0] = x * 3;      // r
+      org_px[1] = x * 3 + 1;  // g
+      org_px[2] = x * 3 + 2;  // b
+      org_px[3] = 0xFF;       // a (opaque)
+    }
+  }
+
+  // encode, making sure it was compressed some
+  std::vector<unsigned char> encoded;
+  EXPECT_TRUE(JPEGCodec::Encode(&original[0], JPEGCodec::FORMAT_RGBA, w, h,
+                                w * 4, jpeg_quality, &encoded));
+  EXPECT_GT(original.size(), encoded.size());
+
+  // decode, it should have the same size as the original
+  std::vector<unsigned char> decoded;
+  int outw, outh;
+  EXPECT_TRUE(JPEGCodec::Decode(&encoded[0], encoded.size(),
+                                JPEGCodec::FORMAT_RGBA, &decoded,
+                                &outw, &outh));
+  ASSERT_EQ(w, outw);
+  ASSERT_EQ(h, outh);
+  ASSERT_EQ(original.size(), decoded.size());
+
+  // Images must be approximately equal (compression will have introduced some
+  // minor artifacts).
+  ASSERT_GE(jpeg_equality_threshold, AveragePixelDelta(original, decoded));
+}
+
+// Test that corrupted data decompression causes failures.
+TEST(JPEGCodec, DecodeCorrupted) {
+  int w = 20, h = 20;
+
+  // some random data (an uncompressed image)
+  std::vector<unsigned char> original;
+  MakeRGBImage(w, h, &original);
+
+  // it should fail when given non-JPEG compressed data
+  std::vector<unsigned char> output;
+  int outw, outh;
+  ASSERT_FALSE(JPEGCodec::Decode(&original[0], original.size(),
+                                 JPEGCodec::FORMAT_RGB, &output,
+                                 &outw, &outh));
+
+  // make some compressed data
+  std::vector<unsigned char> compressed;
+  ASSERT_TRUE(JPEGCodec::Encode(&original[0], JPEGCodec::FORMAT_RGB, w, h,
+                                w * 3, jpeg_quality, &compressed));
+
+  // try decompressing a truncated version
+  ASSERT_FALSE(JPEGCodec::Decode(&compressed[0], compressed.size() / 2,
+                                 JPEGCodec::FORMAT_RGB, &output,
+                                 &outw, &outh));
+
+  // corrupt it and try decompressing that
+  for (int i = 10; i < 30; i++)
+    compressed[i] = i;
+  ASSERT_FALSE(JPEGCodec::Decode(&compressed[0], compressed.size(),
+                                 JPEGCodec::FORMAT_RGB, &output,
+                                 &outw, &outh));
+}
+
+}  // namespace gfx
diff --git a/gfx/codec/png_codec.cc b/gfx/codec/png_codec.cc
new file mode 100644
index 0000000..eaf94f0
--- /dev/null
+++ b/gfx/codec/png_codec.cc
@@ -0,0 +1,690 @@
+// Copyright (c) 2009 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.
+
+#include "gfx/codec/png_codec.h"
+
+#include "base/logging.h"
+#include "base/scoped_ptr.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "third_party/skia/include/core/SkUnPreMultiply.h"
+#include "third_party/skia/include/core/SkColorPriv.h"
+
+extern "C" {
+#if defined(USE_SYSTEM_LIBPNG)
+#include <png.h>
+#else
+#include "third_party/libpng/png.h"
+#endif
+}
+
+namespace gfx {
+
+namespace {
+
+// Converts BGRA->RGBA and RGBA->BGRA.
+void ConvertBetweenBGRAandRGBA(const unsigned char* input, int pixel_width,
+                               unsigned char* output, bool* is_opaque) {
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &input[x * 4];
+    unsigned char* pixel_out = &output[x * 4];
+    pixel_out[0] = pixel_in[2];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[0];
+    pixel_out[3] = pixel_in[3];
+  }
+}
+
+void ConvertRGBAtoRGB(const unsigned char* rgba, int pixel_width,
+                      unsigned char* rgb, bool* is_opaque) {
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &rgba[x * 4];
+    unsigned char* pixel_out = &rgb[x * 3];
+    pixel_out[0] = pixel_in[0];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[2];
+  }
+}
+
+void ConvertRGBtoSkia(const unsigned char* rgb, int pixel_width,
+                      unsigned char* rgba, bool* is_opaque) {
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &rgb[x * 3];
+    uint32_t* pixel_out = reinterpret_cast<uint32_t*>(&rgba[x * 4]);
+    *pixel_out = SkPackARGB32(0xFF, pixel_in[0], pixel_in[1], pixel_in[2]);
+  }
+}
+
+void ConvertRGBAtoSkia(const unsigned char* rgb, int pixel_width,
+                       unsigned char* rgba, bool* is_opaque) {
+  int total_length = pixel_width * 4;
+  for (int x = 0; x < total_length; x += 4) {
+    const unsigned char* pixel_in = &rgb[x];
+    uint32_t* pixel_out = reinterpret_cast<uint32_t*>(&rgba[x]);
+
+    unsigned char alpha = pixel_in[3];
+    if (alpha != 255) {
+      *is_opaque = false;
+      *pixel_out = SkPreMultiplyARGB(alpha,
+           pixel_in[0], pixel_in[1], pixel_in[2]);
+    } else {
+      *pixel_out = SkPackARGB32(alpha,
+           pixel_in[0], pixel_in[1], pixel_in[2]);
+    }
+  }
+}
+
+void ConvertSkiatoRGB(const unsigned char* skia, int pixel_width,
+                      unsigned char* rgb, bool* is_opaque) {
+  for (int x = 0; x < pixel_width; x++) {
+    const uint32_t pixel_in = *reinterpret_cast<const uint32_t*>(&skia[x * 4]);
+    unsigned char* pixel_out = &rgb[x * 3];
+
+    int alpha = SkColorGetA(pixel_in);
+    if (alpha != 0 && alpha != 255) {
+      SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(pixel_in);
+      pixel_out[0] = SkColorGetR(unmultiplied);
+      pixel_out[1] = SkColorGetG(unmultiplied);
+      pixel_out[2] = SkColorGetB(unmultiplied);
+    } else {
+      pixel_out[0] = SkColorGetR(pixel_in);
+      pixel_out[1] = SkColorGetG(pixel_in);
+      pixel_out[2] = SkColorGetB(pixel_in);
+    }
+  }
+}
+
+void ConvertSkiatoRGBA(const unsigned char* skia, int pixel_width,
+                       unsigned char* rgba, bool* is_opaque) {
+  int total_length = pixel_width * 4;
+  for (int i = 0; i < total_length; i += 4) {
+    const uint32_t pixel_in = *reinterpret_cast<const uint32_t*>(&skia[i]);
+
+    // Pack the components here.
+    int alpha = SkColorGetA(pixel_in);
+    if (alpha != 0 && alpha != 255) {
+      SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(pixel_in);
+      rgba[i + 0] = SkColorGetR(unmultiplied);
+      rgba[i + 1] = SkColorGetG(unmultiplied);
+      rgba[i + 2] = SkColorGetB(unmultiplied);
+      rgba[i + 3] = alpha;
+    } else {
+      rgba[i + 0] = SkColorGetR(pixel_in);
+      rgba[i + 1] = SkColorGetG(pixel_in);
+      rgba[i + 2] = SkColorGetB(pixel_in);
+      rgba[i + 3] = alpha;
+    }
+  }
+}
+
+}  // namespace
+
+// Decoder --------------------------------------------------------------------
+//
+// This code is based on WebKit libpng interface (PNGImageDecoder), which is
+// in turn based on the Mozilla png decoder.
+
+namespace {
+
+// Gamma constants: We assume we're on Windows which uses a gamma of 2.2.
+const double kMaxGamma = 21474.83;  // Maximum gamma accepted by png library.
+const double kDefaultGamma = 2.2;
+const double kInverseGamma = 1.0 / kDefaultGamma;
+
+class PngDecoderState {
+ public:
+  // Output is a vector<unsigned char>.
+  PngDecoderState(PNGCodec::ColorFormat ofmt, std::vector<unsigned char>* o)
+      : output_format(ofmt),
+        output_channels(0),
+        bitmap(NULL),
+        is_opaque(true),
+        output(o),
+        row_converter(NULL),
+        width(0),
+        height(0),
+        done(false) {
+  }
+
+  // Output is an SkBitmap.
+  explicit PngDecoderState(SkBitmap* skbitmap)
+      : output_format(PNGCodec::FORMAT_SkBitmap),
+        output_channels(0),
+        bitmap(skbitmap),
+        is_opaque(true),
+        output(NULL),
+        row_converter(NULL),
+        width(0),
+        height(0),
+        done(false) {
+  }
+
+  PNGCodec::ColorFormat output_format;
+  int output_channels;
+
+  // An incoming SkBitmap to write to. If NULL, we write to output instead.
+  SkBitmap* bitmap;
+
+  // Used during the reading of an SkBitmap. Defaults to true until we see a
+  // pixel with anything other than an alpha of 255.
+  bool is_opaque;
+
+  // The other way to decode output, where we write into an intermediary buffer
+  // instead of directly to an SkBitmap.
+  std::vector<unsigned char>* output;
+
+  // Called to convert a row from the library to the correct output format.
+  // When NULL, no conversion is necessary.
+  void (*row_converter)(const unsigned char* in, int w, unsigned char* out,
+                        bool* is_opaque);
+
+  // Size of the image, set in the info callback.
+  int width;
+  int height;
+
+  // Set to true when we've found the end of the data.
+  bool done;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(PngDecoderState);
+};
+
+void ConvertRGBtoRGBA(const unsigned char* rgb, int pixel_width,
+                      unsigned char* rgba, bool* is_opaque) {
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &rgb[x * 3];
+    unsigned char* pixel_out = &rgba[x * 4];
+    pixel_out[0] = pixel_in[0];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[2];
+    pixel_out[3] = 0xff;
+  }
+}
+
+void ConvertRGBtoBGRA(const unsigned char* rgb, int pixel_width,
+                      unsigned char* bgra, bool* is_opaque) {
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &rgb[x * 3];
+    unsigned char* pixel_out = &bgra[x * 4];
+    pixel_out[0] = pixel_in[2];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[0];
+    pixel_out[3] = 0xff;
+  }
+}
+
+// Called when the png header has been read. This code is based on the WebKit
+// PNGImageDecoder
+void DecodeInfoCallback(png_struct* png_ptr, png_info* info_ptr) {
+  PngDecoderState* state = static_cast<PngDecoderState*>(
+      png_get_progressive_ptr(png_ptr));
+
+  int bit_depth, color_type, interlace_type, compression_type;
+  int filter_type, channels;
+  png_uint_32 w, h;
+  png_get_IHDR(png_ptr, info_ptr, &w, &h, &bit_depth, &color_type,
+               &interlace_type, &compression_type, &filter_type);
+
+  // Bounds check. When the image is unreasonably big, we'll error out and
+  // end up back at the setjmp call when we set up decoding.  "Unreasonably big"
+  // means "big enough that w * h * 32bpp might overflow an int"; we choose this
+  // threshold to match WebKit and because a number of places in code assume
+  // that an image's size (in bytes) fits in a (signed) int.
+  unsigned long long total_size =
+      static_cast<unsigned long long>(w) * static_cast<unsigned long long>(h);
+  if (total_size > ((1 << 29) - 1))
+    longjmp(png_jmpbuf(png_ptr), 1);
+  state->width = static_cast<int>(w);
+  state->height = static_cast<int>(h);
+
+  // Expand to ensure we use 24-bit for RGB and 32-bit for RGBA.
+  if (color_type == PNG_COLOR_TYPE_PALETTE ||
+      (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8))
+    png_set_expand(png_ptr);
+
+  // Transparency for paletted images.
+  if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+    png_set_expand(png_ptr);
+
+  // Convert 16-bit to 8-bit.
+  if (bit_depth == 16)
+    png_set_strip_16(png_ptr);
+
+  // Expand grayscale to RGB.
+  if (color_type == PNG_COLOR_TYPE_GRAY ||
+      color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    png_set_gray_to_rgb(png_ptr);
+
+  // Deal with gamma and keep it under our control.
+  double gamma;
+  if (png_get_gAMA(png_ptr, info_ptr, &gamma)) {
+    if (gamma <= 0.0 || gamma > kMaxGamma) {
+      gamma = kInverseGamma;
+      png_set_gAMA(png_ptr, info_ptr, gamma);
+    }
+    png_set_gamma(png_ptr, kDefaultGamma, gamma);
+  } else {
+    png_set_gamma(png_ptr, kDefaultGamma, kInverseGamma);
+  }
+
+  // Tell libpng to send us rows for interlaced pngs.
+  if (interlace_type == PNG_INTERLACE_ADAM7)
+    png_set_interlace_handling(png_ptr);
+
+  // Update our info now
+  png_read_update_info(png_ptr, info_ptr);
+  channels = png_get_channels(png_ptr, info_ptr);
+
+  // Pick our row format converter necessary for this data.
+  if (channels == 3) {
+    switch (state->output_format) {
+      case PNGCodec::FORMAT_RGB:
+        state->row_converter = NULL;  // no conversion necessary
+        state->output_channels = 3;
+        break;
+      case PNGCodec::FORMAT_RGBA:
+        state->row_converter = &ConvertRGBtoRGBA;
+        state->output_channels = 4;
+        break;
+      case PNGCodec::FORMAT_BGRA:
+        state->row_converter = &ConvertRGBtoBGRA;
+        state->output_channels = 4;
+        break;
+      case PNGCodec::FORMAT_SkBitmap:
+        state->row_converter = &ConvertRGBtoSkia;
+        state->output_channels = 4;
+        break;
+      default:
+        NOTREACHED() << "Unknown output format";
+        break;
+    }
+  } else if (channels == 4) {
+    switch (state->output_format) {
+      case PNGCodec::FORMAT_RGB:
+        state->row_converter = &ConvertRGBAtoRGB;
+        state->output_channels = 3;
+        break;
+      case PNGCodec::FORMAT_RGBA:
+        state->row_converter = NULL;  // no conversion necessary
+        state->output_channels = 4;
+        break;
+      case PNGCodec::FORMAT_BGRA:
+        state->row_converter = &ConvertBetweenBGRAandRGBA;
+        state->output_channels = 4;
+        break;
+      case PNGCodec::FORMAT_SkBitmap:
+        state->row_converter = &ConvertRGBAtoSkia;
+        state->output_channels = 4;
+        break;
+      default:
+        NOTREACHED() << "Unknown output format";
+        break;
+    }
+  } else {
+    NOTREACHED() << "Unknown input channels";
+    longjmp(png_jmpbuf(png_ptr), 1);
+  }
+
+  if (state->bitmap) {
+    state->bitmap->setConfig(SkBitmap::kARGB_8888_Config,
+                             state->width, state->height);
+    state->bitmap->allocPixels();
+  } else if (state->output) {
+    state->output->resize(
+        state->width * state->output_channels * state->height);
+  }
+}
+
+void DecodeRowCallback(png_struct* png_ptr, png_byte* new_row,
+                       png_uint_32 row_num, int pass) {
+  PngDecoderState* state = static_cast<PngDecoderState*>(
+      png_get_progressive_ptr(png_ptr));
+
+  DCHECK(pass == 0) << "We didn't turn on interlace handling, but libpng is "
+                       "giving us interlaced data.";
+  if (static_cast<int>(row_num) > state->height) {
+    NOTREACHED() << "Invalid row";
+    return;
+  }
+
+  unsigned char* base = NULL;
+  if (state->bitmap)
+    base = reinterpret_cast<unsigned char*>(state->bitmap->getAddr32(0, 0));
+  else if (state->output)
+    base = &state->output->front();
+
+  unsigned char* dest = &base[state->width * state->output_channels * row_num];
+  if (state->row_converter)
+    state->row_converter(new_row, state->width, dest, &state->is_opaque);
+  else
+    memcpy(dest, new_row, state->width * state->output_channels);
+}
+
+void DecodeEndCallback(png_struct* png_ptr, png_info* info) {
+  PngDecoderState* state = static_cast<PngDecoderState*>(
+      png_get_progressive_ptr(png_ptr));
+
+  // Mark the image as complete, this will tell the Decode function that we
+  // have successfully found the end of the data.
+  state->done = true;
+}
+
+// Automatically destroys the given read structs on destruction to make
+// cleanup and error handling code cleaner.
+class PngReadStructDestroyer {
+ public:
+  PngReadStructDestroyer(png_struct** ps, png_info** pi) : ps_(ps), pi_(pi) {
+  }
+  ~PngReadStructDestroyer() {
+    png_destroy_read_struct(ps_, pi_, NULL);
+  }
+ private:
+  png_struct** ps_;
+  png_info** pi_;
+};
+
+bool BuildPNGStruct(const unsigned char* input, size_t input_size,
+                    png_struct** png_ptr, png_info** info_ptr) {
+  if (input_size < 8)
+    return false;  // Input data too small to be a png
+
+  // Have libpng check the signature, it likes the first 8 bytes.
+  if (png_sig_cmp(const_cast<unsigned char*>(input), 0, 8) != 0)
+    return false;
+
+  *png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+  if (!*png_ptr)
+    return false;
+
+  *info_ptr = png_create_info_struct(*png_ptr);
+  if (!*info_ptr) {
+    png_destroy_read_struct(png_ptr, NULL, NULL);
+    return false;
+  }
+
+  return true;
+}
+
+}  // namespace
+
+// static
+bool PNGCodec::Decode(const unsigned char* input, size_t input_size,
+                      ColorFormat format, std::vector<unsigned char>* output,
+                      int* w, int* h) {
+  png_struct* png_ptr = NULL;
+  png_info* info_ptr = NULL;
+  if (!BuildPNGStruct(input, input_size, &png_ptr, &info_ptr))
+    return false;
+
+  PngReadStructDestroyer destroyer(&png_ptr, &info_ptr);
+  if (setjmp(png_jmpbuf(png_ptr))) {
+    // The destroyer will ensure that the structures are cleaned up in this
+    // case, even though we may get here as a jump from random parts of the
+    // PNG library called below.
+    return false;
+  }
+
+  PngDecoderState state(format, output);
+
+  png_set_progressive_read_fn(png_ptr, &state, &DecodeInfoCallback,
+                              &DecodeRowCallback, &DecodeEndCallback);
+  png_process_data(png_ptr,
+                   info_ptr,
+                   const_cast<unsigned char*>(input),
+                   input_size);
+
+  if (!state.done) {
+    // Fed it all the data but the library didn't think we got all the data, so
+    // this file must be truncated.
+    output->clear();
+    return false;
+  }
+
+  *w = state.width;
+  *h = state.height;
+  return true;
+}
+
+// static
+bool PNGCodec::Decode(const unsigned char* input, size_t input_size,
+                      SkBitmap* bitmap) {
+  DCHECK(bitmap);
+  png_struct* png_ptr = NULL;
+  png_info* info_ptr = NULL;
+  if (!BuildPNGStruct(input, input_size, &png_ptr, &info_ptr))
+    return false;
+
+  PngReadStructDestroyer destroyer(&png_ptr, &info_ptr);
+  if (setjmp(png_jmpbuf(png_ptr))) {
+    // The destroyer will ensure that the structures are cleaned up in this
+    // case, even though we may get here as a jump from random parts of the
+    // PNG library called below.
+    return false;
+  }
+
+  PngDecoderState state(bitmap);
+
+  png_set_progressive_read_fn(png_ptr, &state, &DecodeInfoCallback,
+                              &DecodeRowCallback, &DecodeEndCallback);
+  png_process_data(png_ptr,
+                   info_ptr,
+                   const_cast<unsigned char*>(input),
+                   input_size);
+
+  if (!state.done) {
+    return false;
+  }
+
+  // Set the bitmap's opaqueness based on what we saw.
+  bitmap->setIsOpaque(state.is_opaque);
+
+  return true;
+}
+
+// static
+SkBitmap* PNGCodec::CreateSkBitmapFromBGRAFormat(
+    std::vector<unsigned char>& bgra, int width, int height) {
+  SkBitmap* bitmap = new SkBitmap();
+  bitmap->setConfig(SkBitmap::kARGB_8888_Config, width, height);
+  bitmap->allocPixels();
+
+  bool opaque = false;
+  unsigned char* bitmap_data =
+      reinterpret_cast<unsigned char*>(bitmap->getAddr32(0, 0));
+  for (int i = width * height * 4 - 4; i >= 0; i -= 4) {
+    unsigned char alpha = bgra[i + 3];
+    if (!opaque && alpha != 255) {
+      opaque = false;
+    }
+    bitmap_data[i + 3] = alpha;
+    bitmap_data[i] = (bgra[i] * alpha) >> 8;
+    bitmap_data[i + 1] = (bgra[i + 1] * alpha) >> 8;
+    bitmap_data[i + 2] = (bgra[i + 2] * alpha) >> 8;
+  }
+
+  bitmap->setIsOpaque(opaque);
+  return bitmap;
+}
+
+// Encoder --------------------------------------------------------------------
+//
+// This section of the code is based on nsPNGEncoder.cpp in Mozilla
+// (Copyright 2005 Google Inc.)
+
+namespace {
+
+// Passed around as the io_ptr in the png structs so our callbacks know where
+// to write data.
+struct PngEncoderState {
+  explicit PngEncoderState(std::vector<unsigned char>* o) : out(o) {}
+  std::vector<unsigned char>* out;
+};
+
+// Called by libpng to flush its internal buffer to ours.
+void EncoderWriteCallback(png_structp png, png_bytep data, png_size_t size) {
+  PngEncoderState* state = static_cast<PngEncoderState*>(png_get_io_ptr(png));
+  DCHECK(state->out);
+
+  size_t old_size = state->out->size();
+  state->out->resize(old_size + size);
+  memcpy(&(*state->out)[old_size], data, size);
+}
+
+void ConvertBGRAtoRGB(const unsigned char* bgra, int pixel_width,
+                      unsigned char* rgb, bool* is_opaque) {
+  for (int x = 0; x < pixel_width; x++) {
+    const unsigned char* pixel_in = &bgra[x * 4];
+    unsigned char* pixel_out = &rgb[x * 3];
+    pixel_out[0] = pixel_in[2];
+    pixel_out[1] = pixel_in[1];
+    pixel_out[2] = pixel_in[0];
+  }
+}
+
+// Automatically destroys the given write structs on destruction to make
+// cleanup and error handling code cleaner.
+class PngWriteStructDestroyer {
+ public:
+  PngWriteStructDestroyer(png_struct** ps, png_info** pi) : ps_(ps), pi_(pi) {
+  }
+  ~PngWriteStructDestroyer() {
+    png_destroy_write_struct(ps_, pi_);
+  }
+ private:
+  png_struct** ps_;
+  png_info** pi_;
+
+  DISALLOW_EVIL_CONSTRUCTORS(PngWriteStructDestroyer);
+};
+
+}  // namespace
+
+// static
+bool PNGCodec::Encode(const unsigned char* input, ColorFormat format,
+                      int w, int h, int row_byte_width,
+                      bool discard_transparency,
+                      std::vector<unsigned char>* output) {
+  // Run to convert an input row into the output row format, NULL means no
+  // conversion is necessary.
+  void (*converter)(const unsigned char* in, int w, unsigned char* out,
+                    bool* is_opaque) = NULL;
+
+  int input_color_components, output_color_components;
+  int png_output_color_type;
+  switch (format) {
+    case FORMAT_RGB:
+      input_color_components = 3;
+      output_color_components = 3;
+      png_output_color_type = PNG_COLOR_TYPE_RGB;
+      discard_transparency = false;
+      break;
+
+    case FORMAT_RGBA:
+      input_color_components = 4;
+      if (discard_transparency) {
+        output_color_components = 3;
+        png_output_color_type = PNG_COLOR_TYPE_RGB;
+        converter = ConvertRGBAtoRGB;
+      } else {
+        output_color_components = 4;
+        png_output_color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+        converter = NULL;
+      }
+      break;
+
+    case FORMAT_BGRA:
+      input_color_components = 4;
+      if (discard_transparency) {
+        output_color_components = 3;
+        png_output_color_type = PNG_COLOR_TYPE_RGB;
+        converter = ConvertBGRAtoRGB;
+      } else {
+        output_color_components = 4;
+        png_output_color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+        converter = ConvertBetweenBGRAandRGBA;
+      }
+      break;
+
+    case FORMAT_SkBitmap:
+      input_color_components = 4;
+      if (discard_transparency) {
+        output_color_components = 3;
+        png_output_color_type = PNG_COLOR_TYPE_RGB;
+        converter = ConvertSkiatoRGB;
+      } else {
+        output_color_components = 4;
+        png_output_color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+        converter = ConvertSkiatoRGBA;
+      }
+      break;
+
+    default:
+      NOTREACHED() << "Unknown pixel format";
+      return false;
+  }
+
+  // Row stride should be at least as long as the length of the data.
+  DCHECK(input_color_components * w <= row_byte_width);
+
+  png_struct* png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
+                                                NULL, NULL, NULL);
+  if (!png_ptr)
+    return false;
+  png_info* info_ptr = png_create_info_struct(png_ptr);
+  if (!info_ptr) {
+    png_destroy_write_struct(&png_ptr, NULL);
+    return false;
+  }
+  PngWriteStructDestroyer destroyer(&png_ptr, &info_ptr);
+
+  if (setjmp(png_jmpbuf(png_ptr))) {
+    // The destroyer will ensure that the structures are cleaned up in this
+    // case, even though we may get here as a jump from random parts of the
+    // PNG library called below.
+    return false;
+  }
+
+  // Set our callback for libpng to give us the data.
+  PngEncoderState state(output);
+  png_set_write_fn(png_ptr, &state, EncoderWriteCallback, NULL);
+
+  png_set_IHDR(png_ptr, info_ptr, w, h, 8, png_output_color_type,
+               PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
+               PNG_FILTER_TYPE_DEFAULT);
+  png_write_info(png_ptr, info_ptr);
+
+  if (!converter) {
+    // No conversion needed, give the data directly to libpng.
+    for (int y = 0; y < h; y ++) {
+      png_write_row(png_ptr,
+                    const_cast<unsigned char*>(&input[y * row_byte_width]));
+    }
+  } else {
+    // Needs conversion using a separate buffer.
+    unsigned char* row = new unsigned char[w * output_color_components];
+    for (int y = 0; y < h; y ++) {
+      converter(&input[y * row_byte_width], w, row, NULL);
+      png_write_row(png_ptr, row);
+    }
+    delete[] row;
+  }
+
+  png_write_end(png_ptr, info_ptr);
+  return true;
+}
+
+// static
+bool PNGCodec::EncodeBGRASkBitmap(const SkBitmap& input,
+                                  bool discard_transparency,
+                                  std::vector<unsigned char>* output) {
+  static const int bbp = 4;
+
+  SkAutoLockPixels lock_input(input);
+  DCHECK(input.empty() || input.bytesPerPixel() == bbp);
+
+  return Encode(reinterpret_cast<unsigned char*>(input.getAddr32(0, 0)),
+                FORMAT_SkBitmap, input.width(), input.height(),
+                input.width() * bbp, discard_transparency, output);
+}
+
+}  // namespace gfx
diff --git a/gfx/codec/png_codec.h b/gfx/codec/png_codec.h
new file mode 100644
index 0000000..f9f754a
--- /dev/null
+++ b/gfx/codec/png_codec.h
@@ -0,0 +1,104 @@
+// Copyright (c) 2006-2008 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 GFX_CODEC_PNG_CODEC_H_
+#define GFX_CODEC_PNG_CODEC_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+
+class SkBitmap;
+
+namespace gfx {
+
+// Interface for encoding and decoding PNG data. This is a wrapper around
+// libpng, which has an inconvenient interface for callers. This is currently
+// designed for use in tests only (where we control the files), so the handling
+// isn't as robust as would be required for a browser (see Decode() for more).
+// WebKit has its own more complicated PNG decoder which handles, among other
+// things, partially downloaded data.
+class PNGCodec {
+ public:
+  enum ColorFormat {
+    // 3 bytes per pixel (packed), in RGB order regardless of endianness.
+    // This is the native JPEG format.
+    FORMAT_RGB,
+
+    // 4 bytes per pixel, in RGBA order in memory regardless of endianness.
+    FORMAT_RGBA,
+
+    // 4 bytes per pixel, in BGRA order in memory regardless of endianness.
+    // This is the default Windows DIB order.
+    FORMAT_BGRA,
+
+    // 4 bytes per pixel, in pre-multiplied kARGB_8888_Config format. For use
+    // with directly writing to a skia bitmap.
+    FORMAT_SkBitmap
+  };
+
+  // Encodes the given raw 'input' data, with each pixel being represented as
+  // given in 'format'. The encoded PNG data will be written into the supplied
+  // vector and true will be returned on success. On failure (false), the
+  // contents of the output buffer are undefined.
+  //
+  // When writing alpha values, the input colors are assumed to be post
+  // multiplied.
+  //
+  // w, h: dimensions of the image
+  // row_byte_width: the width in bytes of each row. This may be greater than
+  //   w * bytes_per_pixel if there is extra padding at the end of each row
+  //   (often, each row is padded to the next machine word).
+  // discard_transparency: when true, and when the input data format includes
+  //   alpha values, these alpha values will be discarded and only RGB will be
+  //   written to the resulting file. Otherwise, alpha values in the input
+  //   will be preserved.
+  static bool Encode(const unsigned char* input, ColorFormat format,
+                     int w, int h, int row_byte_width,
+                     bool discard_transparency,
+                     std::vector<unsigned char>* output);
+
+  // Call PNGCodec::Encode on the supplied SkBitmap |input|, which is assumed
+  // to be BGRA, 32 bits per pixel. The params |discard_transparency| and
+  // |output| are passed directly to Encode; refer to Encode for more
+  // information. During the call, an SkAutoLockPixels lock is held on |input|.
+  static bool EncodeBGRASkBitmap(const SkBitmap& input,
+                                 bool discard_transparency,
+                                 std::vector<unsigned char>* output);
+
+  // Decodes the PNG data contained in input of length input_size. The
+  // decoded data will be placed in *output with the dimensions in *w and *h
+  // on success (returns true). This data will be written in the 'format'
+  // format. On failure, the values of these output variables are undefined.
+  //
+  // This function may not support all PNG types, and it hasn't been tested
+  // with a large number of images, so assume a new format may not work. It's
+  // really designed to be able to read in something written by Encode() above.
+  static bool Decode(const unsigned char* input, size_t input_size,
+                     ColorFormat format, std::vector<unsigned char>* output,
+                     int* w, int* h);
+
+  // Decodes the PNG data directly into the passed in SkBitmap. This is
+  // significantly faster than the vector<unsigned char> version of Decode()
+  // above when dealing with PNG files that are >500K, which a lot of theme
+  // images are. (There are a lot of themes that have a NTP image of about ~1
+  // megabyte, and those require a 7-10 megabyte side buffer.)
+  //
+  // Returns true if data is non-null and can be decoded as a png, false
+  // otherwise.
+  static bool Decode(const unsigned char* input, size_t input_size,
+                     SkBitmap* bitmap);
+
+  // Create a SkBitmap from a decoded BGRA DIB. The caller owns the returned
+  // SkBitmap.
+  static SkBitmap* CreateSkBitmapFromBGRAFormat(
+      std::vector<unsigned char>& bgra, int width, int height);
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(PNGCodec);
+};
+
+}  // namespace gfx
+
+#endif  // GFX_CODEC_PNG_CODEC_H_
diff --git a/gfx/codec/png_codec_unittest.cc b/gfx/codec/png_codec_unittest.cc
new file mode 100644
index 0000000..19d1f19
--- /dev/null
+++ b/gfx/codec/png_codec_unittest.cc
@@ -0,0 +1,297 @@
+// Copyright (c) 2006-2008 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.
+
+#include <math.h>
+
+#include "gfx/codec/png_codec.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "third_party/skia/include/core/SkUnPreMultiply.h"
+
+namespace gfx {
+
+static void MakeRGBImage(int w, int h, std::vector<unsigned char>* dat) {
+  dat->resize(w * h * 3);
+  for (int y = 0; y < h; y++) {
+    for (int x = 0; x < w; x++) {
+      unsigned char* org_px = &(*dat)[(y * w + x) * 3];
+      org_px[0] = x * 3;      // r
+      org_px[1] = x * 3 + 1;  // g
+      org_px[2] = x * 3 + 2;  // b
+    }
+  }
+}
+
+// Set use_transparency to write data into the alpha channel, otherwise it will
+// be filled with 0xff. With the alpha channel stripped, this should yield the
+// same image as MakeRGBImage above, so the code below can make reference
+// images for conversion testing.
+static void MakeRGBAImage(int w, int h, bool use_transparency,
+                          std::vector<unsigned char>* dat) {
+  dat->resize(w * h * 4);
+  for (int y = 0; y < h; y++) {
+    for (int x = 0; x < w; x++) {
+      unsigned char* org_px = &(*dat)[(y * w + x) * 4];
+      org_px[0] = x * 3;      // r
+      org_px[1] = x * 3 + 1;  // g
+      org_px[2] = x * 3 + 2;  // b
+      if (use_transparency)
+        org_px[3] = x*3 + 3;  // a
+      else
+        org_px[3] = 0xFF;     // a (opaque)
+    }
+  }
+}
+
+// Returns true if each channel of the given two colors are "close." This is
+// used for comparing colors where rounding errors may cause off-by-one.
+bool ColorsClose(uint32_t a, uint32_t b) {
+  return abs(static_cast<int>(SkColorGetB(a) - SkColorGetB(b))) < 2 &&
+         abs(static_cast<int>(SkColorGetG(a) - SkColorGetG(b))) < 2 &&
+         abs(static_cast<int>(SkColorGetR(a) - SkColorGetR(b))) < 2 &&
+         abs(static_cast<int>(SkColorGetA(a) - SkColorGetA(b))) < 2;
+}
+
+// Returns true if the RGB components are "close."
+bool NonAlphaColorsClose(uint32_t a, uint32_t b) {
+  return abs(static_cast<int>(SkColorGetB(a) - SkColorGetB(b))) < 2 &&
+         abs(static_cast<int>(SkColorGetG(a) - SkColorGetG(b))) < 2 &&
+         abs(static_cast<int>(SkColorGetR(a) - SkColorGetR(b))) < 2;
+}
+
+void MakeTestSkBitmap(int w, int h, SkBitmap* bmp) {
+  bmp->setConfig(SkBitmap::kARGB_8888_Config, w, h);
+  bmp->allocPixels();
+
+  uint32_t* src_data = bmp->getAddr32(0, 0);
+  for (int i = 0; i < w * h; i++) {
+    src_data[i] = SkPreMultiplyARGB(i % 255, i % 250, i % 245, i % 240);
+  }
+}
+
+TEST(PNGCodec, EncodeDecodeRGB) {
+  const int w = 20, h = 20;
+
+  // create an image with known values
+  std::vector<unsigned char> original;
+  MakeRGBImage(w, h, &original);
+
+  // encode
+  std::vector<unsigned char> encoded;
+  EXPECT_TRUE(PNGCodec::Encode(&original[0], PNGCodec::FORMAT_RGB, w, h,
+                               w * 3, false, &encoded));
+
+  // decode, it should have the same size as the original
+  std::vector<unsigned char> decoded;
+  int outw, outh;
+  EXPECT_TRUE(PNGCodec::Decode(&encoded[0], encoded.size(),
+                               PNGCodec::FORMAT_RGB, &decoded,
+                               &outw, &outh));
+  ASSERT_EQ(w, outw);
+  ASSERT_EQ(h, outh);
+  ASSERT_EQ(original.size(), decoded.size());
+
+  // Images must be equal
+  ASSERT_TRUE(original == decoded);
+}
+
+TEST(PNGCodec, EncodeDecodeRGBA) {
+  const int w = 20, h = 20;
+
+  // create an image with known values, a must be opaque because it will be
+  // lost during encoding
+  std::vector<unsigned char> original;
+  MakeRGBAImage(w, h, true, &original);
+
+  // encode
+  std::vector<unsigned char> encoded;
+  EXPECT_TRUE(PNGCodec::Encode(&original[0], PNGCodec::FORMAT_RGBA, w, h,
+                               w * 4, false, &encoded));
+
+  // decode, it should have the same size as the original
+  std::vector<unsigned char> decoded;
+  int outw, outh;
+  EXPECT_TRUE(PNGCodec::Decode(&encoded[0], encoded.size(),
+                               PNGCodec::FORMAT_RGBA, &decoded,
+                               &outw, &outh));
+  ASSERT_EQ(w, outw);
+  ASSERT_EQ(h, outh);
+  ASSERT_EQ(original.size(), decoded.size());
+
+  // Images must be exactly equal
+  ASSERT_TRUE(original == decoded);
+}
+
+// Test that corrupted data decompression causes failures.
+TEST(PNGCodec, DecodeCorrupted) {
+  int w = 20, h = 20;
+
+  // Make some random data (an uncompressed image).
+  std::vector<unsigned char> original;
+  MakeRGBImage(w, h, &original);
+
+  // It should fail when given non-JPEG compressed data.
+  std::vector<unsigned char> output;
+  int outw, outh;
+  EXPECT_FALSE(PNGCodec::Decode(&original[0], original.size(),
+                                PNGCodec::FORMAT_RGB, &output,
+                                &outw, &outh));
+
+  // Make some compressed data.
+  std::vector<unsigned char> compressed;
+  EXPECT_TRUE(PNGCodec::Encode(&original[0], PNGCodec::FORMAT_RGB, w, h,
+                               w * 3, false, &compressed));
+
+  // Try decompressing a truncated version.
+  EXPECT_FALSE(PNGCodec::Decode(&compressed[0], compressed.size() / 2,
+                                PNGCodec::FORMAT_RGB, &output,
+                                &outw, &outh));
+
+  // Corrupt it and try decompressing that.
+  for (int i = 10; i < 30; i++)
+    compressed[i] = i;
+  EXPECT_FALSE(PNGCodec::Decode(&compressed[0], compressed.size(),
+                                PNGCodec::FORMAT_RGB, &output,
+                                &outw, &outh));
+}
+
+TEST(PNGCodec, EncodeDecodeBGRA) {
+  const int w = 20, h = 20;
+
+  // Create an image with known values, alpha must be opaque because it will be
+  // lost during encoding.
+  std::vector<unsigned char> original;
+  MakeRGBAImage(w, h, true, &original);
+
+  // Encode.
+  std::vector<unsigned char> encoded;
+  EXPECT_TRUE(PNGCodec::Encode(&original[0], PNGCodec::FORMAT_BGRA, w, h,
+                               w * 4, false, &encoded));
+
+  // Decode, it should have the same size as the original.
+  std::vector<unsigned char> decoded;
+  int outw, outh;
+  EXPECT_TRUE(PNGCodec::Decode(&encoded[0], encoded.size(),
+                               PNGCodec::FORMAT_BGRA, &decoded,
+                               &outw, &outh));
+  ASSERT_EQ(w, outw);
+  ASSERT_EQ(h, outh);
+  ASSERT_EQ(original.size(), decoded.size());
+
+  // Images must be exactly equal.
+  ASSERT_TRUE(original == decoded);
+}
+
+TEST(PNGCodec, StripAddAlpha) {
+  const int w = 20, h = 20;
+
+  // These should be the same except one has a 0xff alpha channel.
+  std::vector<unsigned char> original_rgb;
+  MakeRGBImage(w, h, &original_rgb);
+  std::vector<unsigned char> original_rgba;
+  MakeRGBAImage(w, h, false, &original_rgba);
+
+  // Encode RGBA data as RGB.
+  std::vector<unsigned char> encoded;
+  EXPECT_TRUE(PNGCodec::Encode(&original_rgba[0],
+                               PNGCodec::FORMAT_RGBA,
+                               w, h,
+                               w * 4, true, &encoded));
+
+  // Decode the RGB to RGBA.
+  std::vector<unsigned char> decoded;
+  int outw, outh;
+  EXPECT_TRUE(PNGCodec::Decode(&encoded[0], encoded.size(),
+                               PNGCodec::FORMAT_RGBA, &decoded,
+                               &outw, &outh));
+
+  // Decoded and reference should be the same (opaque alpha).
+  ASSERT_EQ(w, outw);
+  ASSERT_EQ(h, outh);
+  ASSERT_EQ(original_rgba.size(), decoded.size());
+  ASSERT_TRUE(original_rgba == decoded);
+
+  // Encode RGBA to RGBA.
+  EXPECT_TRUE(PNGCodec::Encode(&original_rgba[0],
+                               PNGCodec::FORMAT_RGBA,
+                               w, h,
+                               w * 4, false, &encoded));
+
+  // Decode the RGBA to RGB.
+  EXPECT_TRUE(PNGCodec::Decode(&encoded[0], encoded.size(),
+                               PNGCodec::FORMAT_RGB, &decoded,
+                               &outw, &outh));
+
+  // It should be the same as our non-alpha-channel reference.
+  ASSERT_EQ(w, outw);
+  ASSERT_EQ(h, outh);
+  ASSERT_EQ(original_rgb.size(), decoded.size());
+  ASSERT_TRUE(original_rgb == decoded);
+}
+
+TEST(PNGCodec, EncodeBGRASkBitmap) {
+  const int w = 20, h = 20;
+
+  SkBitmap original_bitmap;
+  MakeTestSkBitmap(w, h, &original_bitmap);
+
+  // Encode the bitmap.
+  std::vector<unsigned char> encoded;
+  PNGCodec::EncodeBGRASkBitmap(original_bitmap, false, &encoded);
+
+  // Decode the encoded string.
+  SkBitmap decoded_bitmap;
+  EXPECT_TRUE(PNGCodec::Decode(&encoded.front(), encoded.size(),
+                               &decoded_bitmap));
+
+  // Compare the original bitmap and the output bitmap. We use ColorsClose
+  // as SkBitmaps are considered to be pre-multiplied, the unpremultiplication
+  // (in Encode) and repremultiplication (in Decode) can be lossy.
+  for (int x = 0; x < w; x++) {
+    for (int y = 0; y < h; y++) {
+      uint32_t original_pixel = original_bitmap.getAddr32(0, y)[x];
+      uint32_t decoded_pixel = decoded_bitmap.getAddr32(0, y)[x];
+      EXPECT_TRUE(ColorsClose(original_pixel, decoded_pixel));
+    }
+  }
+}
+
+TEST(PNGCodec, EncodeBGRASkBitmapDiscardTransparency) {
+  const int w = 20, h = 20;
+
+  SkBitmap original_bitmap;
+  MakeTestSkBitmap(w, h, &original_bitmap);
+
+  // Encode the bitmap.
+  std::vector<unsigned char> encoded;
+  PNGCodec::EncodeBGRASkBitmap(original_bitmap, true, &encoded);
+
+  // Decode the encoded string.
+  SkBitmap decoded_bitmap;
+  EXPECT_TRUE(PNGCodec::Decode(&encoded.front(), encoded.size(),
+                               &decoded_bitmap));
+
+  // Compare the original bitmap and the output bitmap. We need to
+  // unpremultiply original_pixel, as the decoded bitmap doesn't have an alpha
+  // channel.
+  for (int x = 0; x < w; x++) {
+    for (int y = 0; y < h; y++) {
+      uint32_t original_pixel = original_bitmap.getAddr32(0, y)[x];
+      uint32_t unpremultiplied =
+          SkUnPreMultiply::PMColorToColor(original_pixel);
+      uint32_t decoded_pixel = decoded_bitmap.getAddr32(0, y)[x];
+      EXPECT_TRUE(NonAlphaColorsClose(unpremultiplied, decoded_pixel))
+          << "Original_pixel: ("
+          << SkColorGetR(unpremultiplied) << ", "
+          << SkColorGetG(unpremultiplied) << ", "
+          << SkColorGetB(unpremultiplied) << "), "
+          << "Decoded pixel: ("
+          << SkColorGetR(decoded_pixel) << ", "
+          << SkColorGetG(decoded_pixel) << ", "
+          << SkColorGetB(decoded_pixel) << ")";
+    }
+  }
+}
+
+}  // namespace gfx