move all Config specific APIs into SkBitmapConfig.cpp -- Config is deprecated

src/images/SkDecodingImageGenerator.h

Index: src/images/SkDecodingImageGenerator.h
diff --git a/src/images/SkDecodingImageGenerator.h b/src/images/SkDecodingImageGenerator.h
index 12a49d59c47e6c6b89c248a7bd88341d35633da3..b176e8190fc24e02c3d4ae30d61c900adc1e4337 100644
--- a/src/images/SkDecodingImageGenerator.h
+++ b/src/images/SkDecodingImageGenerator.h
@@ -44,7 +44,7 @@ public:
      *         color-space.  The default is true.
      *
      *  @param fRequestedColorType If not given, then use whichever
-     *         config the decoder wants.  Else try to use this color
+     *         colortype the decoder wants.  Else try to use this color
      *         type.  If the decoder won't support this color type,
      *         SkDecodingImageGenerator::Create will return
      *         NULL. kIndex_8_SkColorType is not supported.
@@ -113,13 +113,14 @@ private:
     const SkImageInfo      fInfo;
     const int              fSampleSize;
     const bool             fDitherImage;
-    const SkBitmap::Config fRequestedConfig;
+    const SkColorType       fRequestedColorType;
+
     SkDecodingImageGenerator(SkData* data,
                              SkStreamRewindable* stream,
                              const SkImageInfo& info,
                              int sampleSize,
                              bool ditherImage,
-                             SkBitmap::Config requestedConfig);
+                             SkColorType requestedColorType);
     static SkImageGenerator* Create(SkData*, SkStreamRewindable*,
                                     const Options&);
     typedef SkImageGenerator INHERITED;