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

core/src/fpdfapi/fpdf_edit/fpdf_edit_content.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 "core/include/fpdfapi/fpdf_module.h"
 #include "core/include/fpdfapi/fpdf_page.h"
 #include "core/include/fpdfapi/fpdf_serial.h"
 #include "core/src/fpdfapi/fpdf_page/pageint.h"
@@ skipping 13 matching lines @@
 FX_BOOL CPDF_PageContentGenerator::InsertPageObject(
     CPDF_PageObject* pPageObject) {
   return pPageObject && m_pageObjects.Add(pPageObject);
 }
 
 void CPDF_PageContentGenerator::GenerateContent() {
   CFX_ByteTextBuf buf;
   CPDF_Dictionary* pPageDict = m_pPage->m_pFormDict;
   for (int i = 0; i < m_pageObjects.GetSize(); ++i) {
     CPDF_PageObject* pPageObj = m_pageObjects[i];
-    if (!pPageObj || pPageObj->m_Type != CPDF_PageObject::IMAGE) {
+    if (!pPageObj || !pPageObj->IsImage()) {
       continue;
     }
-    ProcessImage(buf, (CPDF_ImageObject*)pPageObj);
+    ProcessImage(buf, pPageObj->AsImage());
   }
   CPDF_Object* pContent =
       pPageDict ? pPageDict->GetElementValue("Contents") : NULL;
   if (pContent) {
     pPageDict->RemoveAt("Contents");
   }
   CPDF_Stream* pStream = new CPDF_Stream(NULL, 0, NULL);
   pStream->SetData(buf.GetBuffer(), buf.GetLength(), FALSE, FALSE);
   m_pDocument->AddIndirectObject(pStream);
   pPageDict->SetAtReference("Contents", m_pDocument, pStream->GetObjNum());
@@ skipping 101 matching lines @@
     CPDF_StreamAcc contentStream;
     contentStream.LoadAllData(pStream);
     ProcessForm(buf, contentStream.GetData(), contentStream.GetSize(), matrix);
   }
   CPDF_Stream* pStream = new CPDF_Stream(NULL, 0, NULL);
   pStream->SetData(buf.GetBuffer(), buf.GetLength(), FALSE, FALSE);
   m_pDocument->AddIndirectObject(pStream);
   m_pPage->m_pFormDict->SetAtReference("Contents", m_pDocument,
                                        pStream->GetObjNum());
 }