Add type cast definitions for CPDF_Array.

core/src/fpdfapi/fpdf_render/fpdf_render.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 "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fpdfapi/fpdf_render.h"
 #include "../../../include/fxge/fx_ge.h"
 #include "../fpdf_page/pageint.h"
@@ skipping 1206 matching lines @@
 
   auto it = m_TransferFuncMap.find(pObj);
   if (it != m_TransferFuncMap.end()) {
     CPDF_CountedObject<CPDF_TransferFunc>* pTransferCounter = it->second;
     return pTransferCounter->AddRef();
   }
 
   CPDF_Function* pFuncs[3] = {nullptr, nullptr, nullptr};
   FX_BOOL bUniTransfer = TRUE;
   FX_BOOL bIdentity = TRUE;
-  if (pObj->GetType() == PDFOBJ_ARRAY) {
+  if (CPDF_Array* pArray = pObj->AsArray()) {
     bUniTransfer = FALSE;
-    CPDF_Array* pArray = (CPDF_Array*)pObj;
     if (pArray->GetCount() < 3)
       return nullptr;
 
     for (FX_DWORD i = 0; i < 3; ++i) {
       pFuncs[2 - i] = CPDF_Function::Load(pArray->GetElementValue(i));
       if (!pFuncs[2 - i]) {
         return nullptr;
       }
     }
   } else {
@@ skipping 199 matching lines @@
         item.GetParamType() == CPDF_ContentMarkItem::PropertiesDict) {
       CPDF_Dictionary* pOCG =
           ToDictionary(static_cast<CPDF_Object*>(item.GetParam()));
       if (!CheckOCGVisible(pOCG)) {
         return FALSE;
       }
     }
   }
   return TRUE;
 }