diff -r 000000000000 -r 6474c204b198 image/decoders/nsIconDecoder.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/image/decoders/nsIconDecoder.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,62 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsIconDecoder_h__
+#define nsIconDecoder_h__
+
+#include "Decoder.h"
+
+#include "nsCOMPtr.h"
+
+namespace mozilla {
+namespace image {
+class RasterImage;
+
+//////////////////////////////////////////////////////////////////////////////////////////////
+// The icon decoder is a decoder specifically tailored for loading icons 
+// from the OS. We've defined our own little format to represent these icons
+// and this decoder takes that format and converts it into 24-bit RGB with alpha channel
+// support. It was modeled a bit off the PPM decoder.
+//
+// Assumptions about the decoder:
+// (1) We receive ALL of the data from the icon channel in one OnDataAvailable call. We don't
+//     support multiple ODA calls yet.
+// (2) the format of the incoming data is as follows:
+//     The first two bytes contain the width and the height of the icon. 
+//     The remaining bytes contain the icon data, 4 bytes per pixel, in
+//       ARGB order (platform endianness, A in highest bits, B in lowest
+//       bits), row-primary, top-to-bottom, left-to-right, with
+//       premultiplied alpha.
+//
+//
+//////////////////////////////////////////////////////////////////////////////////////////////
+
+class nsIconDecoder : public Decoder
+{
+public:
+
+  nsIconDecoder(RasterImage &aImage);
+  virtual ~nsIconDecoder();
+
+  virtual void WriteInternal(const char* aBuffer, uint32_t aCount, DecodeStrategy aStrategy);
+
+  uint8_t mWidth;
+  uint8_t mHeight;
+  uint32_t mPixBytesRead;
+  uint32_t mState;
+};
+
+enum {
+  iconStateStart      = 0,
+  iconStateHaveHeight = 1,
+  iconStateReadPixels = 2,
+  iconStateFinished   = 3
+};
+
+} // namespace image
+} // namespace mozilla
+
+#endif // nsIconDecoder_h__