Call standard libjpeg/libjpeg-turbo APIs from SkJpegCodec

src/codec/SkJpegCodec.h

Index: src/codec/SkJpegCodec.h
diff --git a/src/codec/SkJpegCodec.h b/src/codec/SkJpegCodec.h
index ce4fe56d58e552d70d2965e44e5924da4616c455..38e41e757cbe82334cb845d313cc54bd2ede1c68 100644
--- a/src/codec/SkJpegCodec.h
+++ b/src/codec/SkJpegCodec.h
@@ -116,6 +116,9 @@ private:
     bool nativelyScaleToDimensions(uint32_t width, uint32_t height); 
 
     SkAutoTDelete<JpegDecoderMgr> fDecoderMgr;
+    // We will save the state of the decompress struct after reading the header.
+    // This allows us to safely call onGetScaledDimensions() at any time.
+    const int                     fReadyState;
     
     friend class SkJpegScanlineDecoder;