add runtime option to provide data->imagegenerator factory

include/core/SkImageGenerator.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImageGenerator_DEFINED
 #define SkImageGenerator_DEFINED
 
@@ skipping 181 matching lines @@
      *  that the sizes match what it expected. If the sizes do not match, it should return false.
      */
     bool getYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3],
                        SkYUVColorSpace* colorSpace);
 
     /**
      *  If the default image decoder system can interpret the specified (encoded) data, then
      *  this returns a new ImageGenerator for it. Otherwise this returns NULL. Either way
      *  the caller is still responsible for managing their ownership of the data.
      */
-    static SkImageGenerator* NewFromData(SkData*);
+    static SkImageGenerator* NewFromEncoded(SkData*);
 
 protected:
     SkImageGenerator(const SkImageInfo& info) : fInfo(info) {}
 
     virtual SkData* onRefEncodedData();
 
 #ifdef SK_LEGACY_IMAGE_GENERATOR_ENUMS_AND_OPTIONS
     virtual Result onGetPixels(const SkImageInfo& info,
                                void* pixels, size_t rowBytes, const Options&,
                                SkPMColor ctable[], int* ctableCount);
 #else
     virtual bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
                              SkPMColor ctable[], int* ctableCount);
 #endif
     virtual bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3]);
     virtual bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3],
                                  SkYUVColorSpace* colorSpace);
 
 private:
     const SkImageInfo fInfo;
+
+    static SkImageGenerator* NewFromEncodedImpl(SkData*);

[scroggo, 2015/07/09 19:01:15]

Maybe add a comment that the implementation does not need to check for NULL?

[reed1, 2015/07/09 19:05:45]

Will do

 };
 
 #endif  // SkImageGenerator_DEFINED