Enabling ico decoding with use of png and bmp decoders

src/codec/SkCodec_libbmp.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCodec.h"
 #include "SkColorTable.h"
-#include "SkEncodedFormat.h"
 #include "SkImageInfo.h"
 #include "SkMaskSwizzler.h"
 #include "SkStream.h"
 #include "SkSwizzler.h"
 #include "SkTypes.h"
 
 // TODO: rename SkCodec_libbmp files to SkBmpCodec
 // TODO: define a wrapper for SkDebugf that doesn't always print
 /*
  *
  * This class implements the decoding for bmp images
  *
  */
 class SkBmpCodec : public SkCodec {
 public:
 
     /*
      *
      * Describes if rows of the input start at the top or bottom of the image
      *
      */
     enum RowOrder {
         kTopDown_RowOrder,
         kBottomUp_RowOrder
     };
 
     /*
      *
-     * Checks the start of the stream to see if the image is a bitmap
+     * Checks the start of the stream to see if the image is a bmp
      *
      */
     static bool IsBmp(SkStream*);
 
     /*
      *
      * Assumes IsBmp was called and returned true
-     * Creates a bitmap decoder
+     * Creates a bmp decoder
      * Reads enough of the stream to determine the image format
      *
      */
     static SkCodec* NewFromStream(SkStream*);
 
+    /*
+     *
+     * Creates a bmp decoder for a bmp embedded in ico
+     * Reads enough of the stream to determine the image format
+     *
+     */
+    static SkCodec* NewFromIco(SkStream*);
+
 protected:
 
     /*
      *
-     * Initiates the bitmap decode
+     * Initiates the bmp decode
      *
      */
     virtual Result onGetPixels(const SkImageInfo& dstInfo, void* dst,
                                size_t dstRowBytes, const Options&, SkPMColor*,
                                int*) SK_OVERRIDE;
 
     SkEncodedFormat onGetEncodedFormat() const SK_OVERRIDE { return kBMP_SkEncodedFormat; }
+
 private:
 
     /*
      *
-     * Used to define the input format of the bitmap
+     * Used to define the input format of the bmp
      *
      */
     enum BitmapInputFormat {
         kStandard_BitmapInputFormat,
         kRLE_BitmapInputFormat,
         kBitMask_BitmapInputFormat,
         kUnknown_BitmapInputFormat
     };
 
     /*
      *
      * Creates the color table
      *
      */
      bool createColorTable(SkAlphaType alphaType);
 
     /*
      *
+     * Creates a bmp decoder
+     * Reads enough of the stream to determine the image format
+     *
+     */
+    static SkCodec* NewFromStream(SkStream*, bool isIco);
+
+    /*
+     *
      * Performs the bitmap decoding for bit masks input format
      *
      */
     Result decodeMask(const SkImageInfo& dstInfo, void* dst,
                       size_t dstRowBytes);
 
     /*
      *
      * Set an RLE pixel using the color table
      *
@@ skipping 44 matching lines @@
      * @param rowOrder indicates whether rows are ordered top-down or bottom-up
      * @param RLEBytes used only for RLE decodes, as we must decode all
      *                  of the data at once rather than row by row
      *                  it indicates the amount of data left in the stream
      *                  after decoding the headers
      *
      */
     SkBmpCodec(const SkImageInfo& srcInfo, SkStream* stream,
                uint16_t bitsPerPixel, BitmapInputFormat format,
                SkMasks* masks, uint32_t numColors, uint32_t bytesPerColor,
-               uint32_t offset, RowOrder rowOrder, size_t RLEByes);
+               uint32_t offset, RowOrder rowOrder, size_t RLEBytes,
+               bool isIco);
 
     // Fields
     const uint16_t                      fBitsPerPixel;
     const BitmapInputFormat             fInputFormat;
     SkAutoTDelete<SkMasks>              fMasks;          // owned
     SkAutoTDelete<SkColorTable>         fColorTable;     // owned
     uint32_t                            fNumColors;
     const uint32_t                      fBytesPerColor;
     const uint32_t                      fOffset;
     const RowOrder                      fRowOrder;
     const size_t                        fRLEBytes;
+    const bool                          fIsIco;
 
     typedef SkCodec INHERITED;
 };