Switch from nonstd::unique_ptr to std::unique_ptr.

core/src/fxcodec/codec/fx_codec_jpx_opj.cpp

Index: core/src/fxcodec/codec/fx_codec_jpx_opj.cpp
diff --git a/core/src/fxcodec/codec/fx_codec_jpx_opj.cpp b/core/src/fxcodec/codec/fx_codec_jpx_opj.cpp
index d3276450c9ef6c130c306004df3d347c2a665e2d..c185d224f066b58c6bf1bbdfec4911a8426d3dbc 100644
--- a/core/src/fxcodec/codec/fx_codec_jpx_opj.cpp
+++ b/core/src/fxcodec/codec/fx_codec_jpx_opj.cpp
@@ -865,7 +865,7 @@ CCodec_JpxModule::~CCodec_JpxModule() {
 CJPX_Decoder* CCodec_JpxModule::CreateDecoder(const uint8_t* src_buf,
                                               FX_DWORD src_size,
                                               CPDF_ColorSpace* cs) {
-  nonstd::unique_ptr<CJPX_Decoder> decoder(new CJPX_Decoder(cs));
+  std::unique_ptr<CJPX_Decoder> decoder(new CJPX_Decoder(cs));
   return decoder->Init(src_buf, src_size) ? decoder.release() : nullptr;
 }