Consolidate SkCodec functions for handling rewind

src/codec/SkJpegCodec.h

Index: src/codec/SkJpegCodec.h
diff --git a/src/codec/SkJpegCodec.h b/src/codec/SkJpegCodec.h
index 5e2135cdffb71b66faa6a2c1cb24ae895626d31d..62a5bbc4cf0f450eb4f2d92f16be0875bc222c1c 100644
--- a/src/codec/SkJpegCodec.h
+++ b/src/codec/SkJpegCodec.h
@@ -65,6 +65,8 @@ protected:
         return kJPEG_SkEncodedFormat;
     }
 
+    bool onRewind() override;
+
 private:
 
     /*
@@ -101,11 +103,6 @@ private:
     SkJpegCodec(const SkImageInfo& srcInfo, SkStream* stream, JpegDecoderMgr* decoderMgr);
 
     /*
-     * Handles rewinding the input stream if it is necessary
-     */
-    bool handleRewind();
-
-    /*
      * Checks if the conversion between the input image and the requested output
      * image has been implemented
      * Sets the output color space