add new copyTo version to SkBitmap, which takes SkColorType

src/images/SkDecodingImageGenerator.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 SkDecodingImageGenerator_DEFINED
 #define SkDecodingImageGenerator_DEFINED
 
@@ skipping 95 matching lines @@
      *         SkImageGenerator constructor and and unref()ed on deletion.
      */
     static SkImageGenerator* Create(SkData* data, const Options& opt);
 
 private:
     SkData*                fData;
     SkStreamRewindable*    fStream;
     const SkImageInfo      fInfo;
     const int              fSampleSize;
     const bool             fDitherImage;
-    const SkBitmap::Config fRequestedConfig;
+
     SkDecodingImageGenerator(SkData* data,
                              SkStreamRewindable* stream,
                              const SkImageInfo& info,
                              int sampleSize,
-                             bool ditherImage,
-                             SkBitmap::Config requestedConfig);
+                             bool ditherImage);
     static SkImageGenerator* Create(SkData*, SkStreamRewindable*,
                                     const Options&);
     typedef SkImageGenerator INHERITED;
 };
 
 //  // Example of most basic use case:
 //
 //  bool install_data(SkData* data, SkBitmap* dst) {
 //     return SkInstallDiscardablePixelRef(
 //         SkDecodingImageGenerator::Create(
 //             data, SkDecodingImageGenerator::Options()), dst, NULL);
 //  }
 //  bool install_stream(SkStreamRewindable* stream, SkBitmap* dst) {
 //     return SkInstallDiscardablePixelRef(
 //         SkDecodingImageGenerator::Create(
 //             stream, SkDecodingImageGenerator::Options()), dst, NULL);
 //  }
 
 #endif  // SkDecodingImageGenerator_DEFINED