Fix crashing in CPDFXFA_Document::GetPage()

fpdfsdk/include/fsdk_mgr.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_MGR_H_
 #define FPDFSDK_INCLUDE_FSDK_MGR_H_
 
 #include <map>
@@ skipping 617 matching lines @@
   bool IsValidAnnot(const CPDF_Annot* p) const;
   void GetCurrentMatrix(CFX_Matrix& matrix) { matrix = m_curMatrix; }
   void UpdateRects(CFX_RectArray& rects);
   void UpdateView(CPDFSDK_Annot* pAnnot);
   const std::vector<CPDFSDK_Annot*>& GetAnnotList() const {
     return m_fxAnnotArray;
   }
 
   int GetPageIndex();
   void LoadFXAnnots();
+  void ClearFXAnnots();
   void SetValid(FX_BOOL bValid) { m_bValid = bValid; }
   FX_BOOL IsValid() { return m_bValid; }
   void SetLock(FX_BOOL bLocked) { m_bLocked = bLocked; }
   FX_BOOL IsLocked() { return m_bLocked; }
 #ifndef PDF_ENABLE_XFA
   void TakeOverPage() { m_bTakeOverPage = TRUE; }
 #endif  // PDF_ENABLE_XFA
 
  private:
   void PageView_OnHighlightFormFields(CFX_RenderDevice* pDevice,
@@ skipping 84 matching lines @@
     }
 
     if (nStartPos < m)
       QuickSort(nStartPos, m, bAscend, pCompare);
     if (nStopPos > m)
       QuickSort(m, nStopPos, bAscend, pCompare);
   }
 };
 
 #endif  // FPDFSDK_INCLUDE_FSDK_MGR_H_