Remove PageObject's m_Type and add As<Type> functions

fpdfsdk/src/javascript/Document.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 "fpdfsdk/src/javascript/Document.h"
 
 #include "fpdfsdk/include/fsdk_mgr.h"  // For CPDFDoc_Environment.
 #include "fpdfsdk/include/javascript/IJavaScript.h"
@@ skipping 1365 matching lines @@
   if (!pPageDict)
     return FALSE;
 
   CPDF_Page page;
   page.Load(pDocument, pPageDict);
   page.ParseContent(nullptr);
 
   int nWords = 0;
   CFX_WideString swRet;
   for (auto& pPageObj : *page.GetPageObjectList()) {
-    if (pPageObj->m_Type == CPDF_PageObject::TEXT) {
-      CPDF_TextObject* pTextObj = static_cast<CPDF_TextObject*>(pPageObj.get());
+    if (pPageObj->IsText()) {
+      CPDF_TextObject* pTextObj = pPageObj->AsText();
       int nObjWords = CountWords(pTextObj);
       if (nWords + nObjWords >= nWordNo) {
         swRet = GetObjWordStr(pTextObj, nWordNo - nWords);
         break;
       }
       nWords += nObjWords;
     }
   }
 
   if (bStrip) {
@@ skipping 33 matching lines @@
   CPDF_Dictionary* pPageDict = pDocument->GetPage(nPageNo);
   if (!pPageDict)
     return FALSE;
 
   CPDF_Page page;
   page.Load(pDocument, pPageDict);
   page.ParseContent(nullptr);
 
   int nWords = 0;
   for (auto& pPageObj : *page.GetPageObjectList()) {
-    if (pPageObj->m_Type == CPDF_PageObject::TEXT)
-      nWords += CountWords(static_cast<CPDF_TextObject*>(pPageObj.get()));
+    if (pPageObj->IsText())
+      nWords += CountWords(pPageObj->AsText());
   }
 
   vRet = nWords;
   return TRUE;
 }
 
 FX_BOOL Document::getPrintParams(IJS_Context* cc,
                                  const std::vector<CJS_Value>& params,
                                  CJS_Value& vRet,
                                  CFX_WideString& sError) {
@@ skipping 171 matching lines @@
     CJS_DelayData* pData = DelayDataForFieldAndControlIndex.GetAt(i);
     Field::DoDelay(m_pDocument, pData);
     DelayDataForFieldAndControlIndex.SetAt(i, NULL);
     delete pData;
   }
 }
 
 CJS_Document* Document::GetCJSDoc() const {
   return static_cast<CJS_Document*>(m_pJSObject);
 }