Call CXFA_Object::ToNode() rather than C-style casting.

xfa/src/fxfa/src/app/xfa_ffdochandler.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 "xfa/src/foxitlib.h"
 #include "xfa/src/fxfa/src/common/xfa_common.h"
 #include "xfa_ffdochandler.h"
 #include "xfa_ffdoc.h"
@@ skipping 61 matching lines @@
   if (!pScriptContext) {
     return NULL;
   }
   return pScriptContext->GetJSValueFromMap(pXFADoc->GetRoot());
 }
 XFA_ATTRIBUTEENUM CXFA_FFDocHandler::GetRestoreState(IXFA_Doc* hDoc) {
   CXFA_Document* pXFADoc = static_cast<CXFA_FFDoc*>(hDoc)->GetXFADoc();
   if (!pXFADoc) {
     return XFA_ATTRIBUTEENUM_Unknown;
   }
-  CXFA_Node* pForm = (CXFA_Node*)pXFADoc->GetXFAObject(XFA_HASHCODE_Form);
+  CXFA_Node* pForm = ToNode(pXFADoc->GetXFAObject(XFA_HASHCODE_Form));
   if (!pForm) {
     return XFA_ATTRIBUTEENUM_Unknown;
   }
   CXFA_Node* pSubForm = pForm->GetFirstChildByClass(XFA_ELEMENT_Subform);
   if (!pSubForm) {
     return XFA_ATTRIBUTEENUM_Unknown;
   }
   return pSubForm->GetEnum(XFA_ATTRIBUTE_RestoreState);
 }
 FX_BOOL CXFA_FFDocHandler::RunDocScript(IXFA_Doc* hDoc,
                                         XFA_SCRIPTTYPE eScriptType,
                                         const CFX_WideStringC& wsScript,
                                         FXJSE_HVALUE hRetValue,
                                         FXJSE_HVALUE hThisObject) {
   CXFA_Document* pXFADoc = static_cast<CXFA_FFDoc*>(hDoc)->GetXFADoc();
   if (!pXFADoc) {
     return FALSE;
   }
   IXFA_ScriptContext* pScriptContext = pXFADoc->GetScriptContext();
   if (!pScriptContext) {
     return FALSE;
   }
   return pScriptContext->RunScript(
       (XFA_SCRIPTLANGTYPE)eScriptType, wsScript, hRetValue,
       hThisObject ? (CXFA_Object*)FXJSE_Value_ToObject(hThisObject, NULL)
                   : NULL);
 }