Make SkAndroidCodec support ico

src/codec/SkSwizzler.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.
  */
 
 #ifndef SkSwizzler_DEFINED
 #define SkSwizzler_DEFINED
 
@@ skipping 145 matching lines @@
 
     /**
      * Implement fill using a custom width.
      */
     void fill(const SkImageInfo& info, void* dst, size_t rowBytes, uint32_t colorOrIndex,
             SkCodec::ZeroInitialized zeroInit) override {
         const SkImageInfo fillInfo = info.makeWH(fAllocatedWidth, info.height());
         SkSampler::Fill(fillInfo, dst, rowBytes, colorOrIndex, zeroInit);
     }
 
+    /**
+     *  Getter for fSampleX.

[scroggo, 2015/12/03 19:39:25]

This line doesn't state anything that cannot be gleaned from looking at the
code.

I think this should say something about what it means - the swizzler is sampling
every sampleX'th pixel (and discarding the rest).

[msarett, 2015/12/03 19:54:15]

Done.

+     *
+     *  Currently used by SkBmpStandardCodec for Bmp-in-Ico decodes.  Ideally, the
+     *  subclasses of SkCodec would have no knowledge of sampling, but this allows
+     *  us to apply a transparency mask to pixels after swizzling.
+     */
+    int sampleX() const { return fSampleX; }
+
 private:
 
     /**
      *  Method for converting raw data to Skia pixels.
      *  @param dstRow Row in which to write the resulting pixels.
      *  @param src Row of src data, in format specified by SrcConfig
      *  @param dstWidth Width in pixels of the destination
      *  @param bpp if bitsPerPixel % 8 == 0, deltaSrc is bytesPerPixel
      *             else, deltaSrc is bitsPerPixel
      *  @param deltaSrc bpp * sampleX
@@ skipping 93 matching lines @@
                                           //     fBPP is bitsPerPixel
     const int           fDstBPP;          // Bytes per pixel for the destination color type
 
     SkSwizzler(RowProc proc, const SkPMColor* ctable, int srcOffset, int srcWidth, int dstOffset,
             int dstWidth, int srcBPP, int dstBPP);
 
     int onSetSampleX(int) override;
 
 };
 #endif // SkSwizzler_DEFINED