Add NewFromStream and getEncodedFormat to BitmapRegionDecoder

tools/SkBitmapRegionDecoderInterface.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 SkBitmapRegionDecoder_DEFINED
 #define SkBitmapRegionDecoder_DEFINED
 
 #include "SkBitmap.h"
+#include "SkEncodedFormat.h"
 #include "SkStream.h"
 
 /*
  * This class aims to provide an interface to test multiple implementations of
  * SkBitmapRegionDecoder.
  */
 class SkBitmapRegionDecoderInterface {
 public:
 
     enum Strategy {
         kCanvas_Strategy,       // Draw to the canvas, uses SkCodec
         kOriginal_Strategy,     // Sampling, uses SkImageDecoder
         kAndroidCodec_Strategy, // Uses SkAndroidCodec for scaling and subsetting
     };
 
     /*
      * @param data     Refs the data while this object exists, unrefs on destruction
      * @param strategy Strategy used for scaling and subsetting
      * @return         Tries to create an SkBitmapRegionDecoder, returns NULL on failure
      */
     static SkBitmapRegionDecoderInterface* CreateBitmapRegionDecoder(
             SkData* data, Strategy strategy);
 
     /*
+     * @param stream   Takes ownership of the stream
+     * @param strategy Strategy used for scaling and subsetting
+     * @return         Tries to create an SkBitmapRegionDecoder, returns NULL on failure
+     */
+    static SkBitmapRegionDecoderInterface* CreateBitmapRegionDecoder(
+            SkStreamRewindable* stream, Strategy strategy);
+
+    /*
      * Decode a scaled region of the encoded image stream
      *
      * @param bitmap          Container for decoded pixels.  It is assumed that the pixels
      *                        are initially unallocated and will be allocated by this function.
      * @param allocator       Allocator for the pixels.  If this is NULL, the default
      *                        allocator (HeapAllocator) will be used.
      * @param desiredSubset   Subset of the original image to decode.
      * @param sampleSize      An integer downscaling factor for the decode.
      * @param colorType       Preferred output colorType.
      *                        New implementations should return NULL if they do not support
      *                        decoding to this color type.
      *                        The old kOriginal_Strategy will decode to a default color type
      *                        if this color type is unsupported.
      * @param requireUnpremul If the image is not opaque, we will use this to determine the
      *                        alpha type to use.
      *
      */
     virtual bool decodeRegion(SkBitmap* bitmap, SkBitmap::Allocator* allocator,
                               const SkIRect& desiredSubset, int sampleSize,
                               SkColorType colorType, bool requireUnpremul) = 0;
     /*
      * @param  Requested destination color type
      * @return true if we support the requested color type and false otherwise
      */
     virtual bool conversionSupported(SkColorType colorType) = 0;
 
+    virtual SkEncodedFormat getEncodedFormat() = 0;
+
     int width() const { return fWidth; }
     int height() const { return fHeight; }
 
     virtual ~SkBitmapRegionDecoderInterface() {}
 
 protected:
 
     SkBitmapRegionDecoderInterface(int width, int height)
         : fWidth(width)
         , fHeight(height)
     {}
 
 private:
     const int fWidth;
     const int fHeight;
 };
 
 #endif