Remove core/fxcodec/codec/codec_int.h.

Move remaining JPX bits into core/fxcodec/jpx/jpx_decode_utils.h.
Reorganize code so jpx_decode_utils.h and jpx_decode_utils.cpp match.
Also move affected code into namespace fxcodec.

Change-Id: I53a5b9843d76f4528ff0308f418a5a8ac998dca7
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/56354
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fxcodec/jpx/cjpx_decoder.h b/core/fxcodec/jpx/cjpx_decoder.h
index 8c607e2..11d94c1 100644
--- a/core/fxcodec/jpx/cjpx_decoder.h
+++ b/core/fxcodec/jpx/cjpx_decoder.h
@@ -10,16 +10,19 @@
 #include <memory>
 #include <vector>
 
-#include "core/fxcodec/codec/codec_int.h"
 #include "core/fxcrt/unowned_ptr.h"
 #include "third_party/base/span.h"
 
-#ifdef USE_SYSTEM_LIBOPENJPEG2
+#if defined(USE_SYSTEM_LIBOPENJPEG2)
 #include <openjpeg.h>
 #else
 #include "third_party/libopenjpeg20/openjpeg.h"
 #endif
 
+namespace fxcodec {
+
+struct DecodeData;
+
 class CJPX_Decoder {
  public:
   enum ColorSpaceOption {
@@ -28,6 +31,8 @@
     kIndexedColorSpace
   };
 
+  static void Sycc420ToRgbForTesting(opj_image_t* img);
+
   explicit CJPX_Decoder(ColorSpaceOption option);
   ~CJPX_Decoder();
 
@@ -48,4 +53,8 @@
   opj_dparameters_t m_Parameters;
 };
 
+}  // namespace fxcodec
+
+using fxcodec::CJPX_Decoder;
+
 #endif  // CORE_FXCODEC_JPX_CJPX_DECODER_H_