Inflict PPDF_ENABLE_XFA ifdefs on XFA core/

core/src/fxcrt/extension.h

Index: core/src/fxcrt/extension.h
diff --git a/core/src/fxcrt/extension.h b/core/src/fxcrt/extension.h
index 718c8f0423d451e3e125ad45e7542722ed2c790a..42cebdf60575d8d9856e99f88ebb782d6771e1b3 100644
--- a/core/src/fxcrt/extension.h
+++ b/core/src/fxcrt/extension.h
@@ -31,6 +31,7 @@ class IFXCRT_FileAccess {
 };
 IFXCRT_FileAccess* FXCRT_FileAccess_Create();
 
+#ifdef PDF_ENABLE_XFA
 class CFX_CRTFileAccess : public IFX_FileAccess {
  public:
   CFX_CRTFileAccess() : m_RefCount(0) {}
@@ -63,6 +64,7 @@ class CFX_CRTFileAccess : public IFX_FileAccess {
   FX_DWORD m_RefCount;
 };
 
+#endif
 class CFX_CRTFileStream final : public IFX_FileStream {
  public:
   CFX_CRTFileStream(IFXCRT_FileAccess* pFA) : m_pFile(pFA), m_dwCount(1) {}