Split off CPDF_Document into its own .cpp/.h files.

fpdfsdk/src/fpdfsave.cpp

 // 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
 
 #include "public/fpdf_save.h"
 
+#include "core/include/fpdfapi/cpdf_document.h"
 #include "core/include/fpdfapi/fpdf_parser.h"
 #include "core/include/fpdfapi/fpdf_serial.h"
 #include "fpdfsdk/include/fsdk_define.h"
 #include "public/fpdf_edit.h"
 
 #ifdef PDF_ENABLE_XFA
 #include "fpdfsdk/include/fpdfxfa/fpdfxfa_app.h"
 #include "fpdfsdk/include/fpdfxfa/fpdfxfa_doc.h"
 #include "fpdfsdk/include/fpdfxfa/fpdfxfa_util.h"
 #include "public/fpdf_formfill.h"
@@ skipping 295 matching lines @@
                                             FPDF_DWORD flags) {
   return FPDF_Doc_Save(document, pFileWrite, flags, FALSE, 0);
 }
 
 DLLEXPORT FPDF_BOOL STDCALL FPDF_SaveWithVersion(FPDF_DOCUMENT document,
                                                  FPDF_FILEWRITE* pFileWrite,
                                                  FPDF_DWORD flags,
                                                  int fileVersion) {
   return FPDF_Doc_Save(document, pFileWrite, flags, TRUE, fileVersion);
 }