Introduce "underlying types" to abstract XFA differences.

fpdfsdk/include/fsdk_baseannot.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 FPDFSDK_INCLUDE_FSDK_BASEANNOT_H_
 #define FPDFSDK_INCLUDE_FSDK_BASEANNOT_H_
 
 #if _FX_OS_ == _FX_ANDROID_
 #include "time.h"
 #else
 #include <ctime>
 #endif
 
 #include "core/include/fpdfdoc/fpdf_doc.h"
 #include "core/include/fxcrt/fx_basic.h"
-#include "fx_systemhandler.h"
+#include "fpdfsdk/include/fsdk_define.h"
+#include "fpdfsdk/include/fx_systemhandler.h"
 
 class CPDFSDK_PageView;
 class CPDF_Annot;
 class CPDF_Page;
 class CPDF_Rect;
 class CPDF_Matrix;
 class CPDF_RenderOptions;
 class CFX_RenderDevice;
 
 #define CFX_IntArray CFX_ArrayTemplate<int>
@@ skipping 55 matching lines @@
   virtual CFX_ByteString GetType() const { return ""; }
   virtual CFX_ByteString GetSubType() const { return ""; }
 
   virtual void SetRect(const CPDF_Rect& rect) {}
   virtual CPDF_Rect GetRect() const { return CPDF_Rect(); }
 
   virtual void Annot_OnDraw(CFX_RenderDevice* pDevice,
                             CPDF_Matrix* pUser2Device,
                             CPDF_RenderOptions* pOptions) {}
 
+  UnderlyingPageType* GetUnderlyingPage();
   CPDF_Page* GetPDFPage();
   CPDFXFA_Page* GetPDFXFAPage();
 
   void SetPage(CPDFSDK_PageView* pPageView) { m_pPageView = pPageView; }
   CPDFSDK_PageView* GetPageView() const { return m_pPageView; }
 
   // Tab Order
   int GetTabOrder();
   void SetTabOrder(int iTabOrder);
 
@@ skipping 98 matching lines @@
                        const CFX_ByteString& sAPState = "");
 
  protected:
   CPDF_Annot* m_pAnnot;
 
  private:
   FX_BOOL CreateFormFiller();
 };
 
 #endif  // FPDFSDK_INCLUDE_FSDK_BASEANNOT_H_