Revert of Delete SkImageDecoder

src/images/SkJpegUtility.h

Index: src/images/SkJpegUtility.h
diff --git a/src/images/SkJpegUtility.h b/src/images/SkJpegUtility.h
index c84465289c2e63dea59708af4c00904c6d564706..1a763f843c7473cd1f57957854b7584e20b065d5 100644
--- a/src/images/SkJpegUtility.h
+++ b/src/images/SkJpegUtility.h
@@ -10,6 +10,7 @@
 #ifndef SkJpegUtility_DEFINED
 #define SkJpegUtility_DEFINED
 
+#include "SkImageDecoder.h"
 #include "SkStream.h"
 
 extern "C" {
@@ -29,6 +30,23 @@
 
 void skjpeg_error_exit(j_common_ptr cinfo);
 
+///////////////////////////////////////////////////////////////////////////
+/* Our source struct for directing jpeg to our stream object.
+*/
+struct skjpeg_source_mgr : jpeg_source_mgr {
+    skjpeg_source_mgr(SkStream* stream, SkImageDecoder* decoder);
+
+    // Unowned.
+    SkStream*       fStream;
+    // Unowned pointer to the decoder, used to check if the decoding process
+    // has been cancelled.
+    SkImageDecoder* fDecoder;
+    enum {
+        kBufferSize = 1024
+    };
+    char    fBuffer[kBufferSize];
+};
+
 /////////////////////////////////////////////////////////////////////////////
 /* Our destination struct for directing decompressed pixels to our stream
  * object.