Make SkAndroidCodec support ico

include/codec/SkCodec.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 SkCodec_DEFINED
 #define SkCodec_DEFINED
 
@@ skipping 364 matching lines @@
          * a single call to getScanlines().
          *
          * Interlaced pngs are an example.
          */
         kNone_SkScanlineOrder,
     };
 
     /**
      *  An enum representing the order in which scanlines will be returned by
      *  the scanline decoder.
+     *
+     *  This is undefined before startScanlineDecode() is called.
      */
     SkScanlineOrder getScanlineOrder() const { return this->onGetScanlineOrder(); }
 
     /**
      *  Returns the y-coordinate of the next row to be returned by the scanline
      *  decoder.
      *
      *  This will equal fCurrScanline, except in the case of strangely
      *  encoded image types (bottom-up bmps, interlaced gifs).
      *
@@ skipping 192 matching lines @@
      *  Return an object which will allow forcing scanline decodes to sample in X.
      *
      *  May create a sampler, if one is not currently being used. Otherwise, does
      *  not affect ownership.
      *
      *  Only valid during scanline decoding.
      */
     virtual SkSampler* getSampler(bool /*createIfNecessary*/) { return nullptr; }
 
     friend class SkSampledCodec;
+    friend class SkIcoCodec;
 };
 #endif // SkCodec_DEFINED