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

fpdfsdk/src/fpdfformfill.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_formfill.h"
 
 #include <memory>
 #include <vector>
 
+#include "core/include/fpdfapi/cpdf_document.h"
 #include "fpdfsdk/include/fsdk_define.h"
 #include "fpdfsdk/include/fsdk_mgr.h"
 #include "public/fpdfview.h"
 #include "third_party/base/stl_util.h"
 
 #ifdef PDF_ENABLE_XFA
 #include "fpdfsdk/include/fpdfxfa/fpdfxfa_app.h"
 #include "fpdfsdk/include/fpdfxfa/fpdfxfa_doc.h"
 #include "fpdfsdk/include/fpdfxfa/fpdfxfa_page.h"
 #endif  // PDF_ENABLE_XFA
@@ skipping 700 matching lines @@
         pActionHandler->DoAction_Page(action, CPDF_AAction::OpenPage, pSDKDoc);
       }
     } else {
       if (aa.ActionExist(CPDF_AAction::ClosePage)) {
         CPDF_Action action = aa.GetAction(CPDF_AAction::ClosePage);
         pActionHandler->DoAction_Page(action, CPDF_AAction::ClosePage, pSDKDoc);
       }
     }
   }
 }