Add type cast definitions for CPDF_Array.

fpdfsdk/src/fpdfview.cpp

Index: fpdfsdk/src/fpdfview.cpp
diff --git a/fpdfsdk/src/fpdfview.cpp b/fpdfsdk/src/fpdfview.cpp
index 0d6dcf29f18e0c4041f78b7ad2f0893debad0267..7c4ffcba59a0a5707789c7d36e72aa984ab531ec 100644
--- a/fpdfsdk/src/fpdfview.cpp
+++ b/fpdfsdk/src/fpdfview.cpp
@@ -881,14 +881,15 @@ DLLEXPORT FPDF_DEST STDCALL FPDF_GetNamedDest(FPDF_DOCUMENT document,
     pDestObj = nameTree.LookupValue(index, bsName);
   }
   if (!pDestObj)
-    return NULL;
+    return nullptr;
   if (CPDF_Dictionary* pDict = pDestObj->AsDictionary()) {
     pDestObj = pDict->GetArray(FX_BSTRC("D"));
     if (!pDestObj)
-      return NULL;
+      return nullptr;
   }
-  if (pDestObj->GetType() != PDFOBJ_ARRAY)
-    return NULL;
+  if (!pDestObj->IsArray())
+    return nullptr;
+
   CFX_WideString wsName = PDF_DecodeText(bsName);
   CFX_ByteString utf16Name = wsName.UTF16LE_Encode();
   unsigned int len = utf16Name.GetLength();