FPDF_Creator can only create file through embedder-supplied callback.

core/include/fpdfapi/fpdf_serial.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef CORE_INCLUDE_FPDFAPI_FPDF_SERIAL_H_
 #define CORE_INCLUDE_FPDFAPI_FPDF_SERIAL_H_
 
 #include "fpdf_page.h"
 #include "fpdf_pageobj.h"
 
 class CPDF_ObjectStream;
 class CPDF_XRefStream;
 CFX_ByteTextBuf& operator<<(CFX_ByteTextBuf& buf, const CPDF_Object* pObj);
 #define FPDFCREATE_INCREMENTAL 1
 #define FPDFCREATE_NO_ORIGINAL 2
 #define FPDFCREATE_PROGRESSIVE 4
 #define FPDFCREATE_OBJECTSTREAM 8
+
 class CPDF_Creator {
  public:
   CPDF_Creator(CPDF_Document* pDoc);
-
   ~CPDF_Creator();
 
   void RemoveSecurity();
-
-  FX_BOOL Create(const FX_WCHAR* filename, FX_DWORD flags = 0);
-
-  FX_BOOL Create(const FX_CHAR* filename, FX_DWORD flags = 0);
-
   FX_BOOL Create(IFX_StreamWrite* pFile, FX_DWORD flags = 0);
-
   int32_t Continue(IFX_Pause* pPause = NULL);
-
   FX_BOOL SetFileVersion(int32_t fileVersion = 17);
 
  protected:
   CPDF_Document* m_pDocument;
 
   CPDF_Parser* m_pParser;
 
   FX_BOOL m_bCompress;
 
   FX_BOOL m_bSecurityChanged;
@@ skipping 59 matching lines @@
   CFX_DWordArray m_NewObjNumArray;
 
   CPDF_Array* m_pIDArray;
 
   int32_t m_FileVersion;
   friend class CPDF_ObjectStream;
   friend class CPDF_XRefStream;
 };
 
 #endif  // CORE_INCLUDE_FPDFAPI_FPDF_SERIAL_H_