XFA: Fix a crashier in SetFocus()

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 432 matching lines @@
       }
       CFX_ByteString bsRet = CFX_ByteString(pbuff, nActualLen);
       CFX_WideString wsRet = CFX_WideString::FromUTF16LE(
           (unsigned short*)bsRet.GetBuffer(bsRet.GetLength()),
           bsRet.GetLength() / sizeof(unsigned short));
       delete[] pbuff;
       return wsRet;
     }
     return L"";
   }
+  void FFI_PageEvent(int iPageIndex, int iEventType) const {
+    if (!m_pInfo || !m_pInfo->FFI_PageEvent)
+      return;
+    m_pInfo->FFI_PageEvent(m_pInfo, iPageIndex, iEventType);
+  }
 #endif  // PDF_ENABLE_XFA
 
   FX_BOOL IsJSInitiated() const { return m_pInfo && m_pInfo->m_pJsPlatform; }
   void SetSDKDocument(CPDFSDK_Document* pFXDoc) { m_pSDKDoc = pFXDoc; }
   CPDFSDK_Document* GetSDKDocument() const { return m_pSDKDoc; }
   UnderlyingDocumentType* GetUnderlyingDocument() const {
     return m_pUnderlyingDoc;
   }
   CFX_ByteString GetAppName() const { return ""; }
   IFX_SystemHandler* GetSysHandler() const { return m_pSysHandler.get(); }
@@ skipping 269 matching lines @@
     }
 
     if (nStartPos < m)
       QuickSort(nStartPos, m, bAscend, pCompare);
     if (nStopPos > m)
       QuickSort(m, nStopPos, bAscend, pCompare);
   }
 };
 
 #endif  // FPDFSDK_INCLUDE_FSDK_MGR_H_