Move the JPEG and PNG codecs from base/gfx to app/gfx/codec. Move the classes...

app/gfx/codec/png_codec.h

 // 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 BASE_GFX_PNG_DECODER_H_
-#define BASE_GFX_PNG_DECODER_H_
+#ifndef APP_GFX_CODEC_PNG_CODEC_H_
+#define APP_GFX_CODEC_PNG_CODEC_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 
 class SkBitmap;
 
-// Interface for 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 PNGDecoder {
+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
   };
 
+  // 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);
 
   // A convenience function for decoding PNGs as previously encoded by the PNG
-  // encoder. Chrome encodes png in the format PNGDecoder::FORMAT_BGRA.
+  // encoder. Chrome encodes png in the format PNGCodec::FORMAT_BGRA.
   //
   // Returns true if data is non-null and can be decoded as a png, false
   // otherwise.
   static bool Decode(const std::vector<unsigned char>* data, SkBitmap* icon);
 
   // 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(PNGDecoder);
+  DISALLOW_COPY_AND_ASSIGN(PNGCodec);
 };
 
-#endif  // BASE_GFX_PNG_DECODER_H_
+}  // namespace gfx
+
+#endif  // APP_GFX_CODEC_PNG_CODEC_H_