Add some consts and remove more casts in core/

core/fpdftext/fpdf_text_int.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 <algorithm>
 #include <cctype>
 #include <cwctype>
 #include <memory>
@@ skipping 990 matching lines @@
       break;
     }
   }
   if (i < 0) {
     m_LineObj.InsertAt(0, Obj);
   }
 }
 
 FPDFText_MarkedContent CPDF_TextPage::PreMarkedContent(PDFTEXT_Obj Obj) {
   CPDF_TextObject* pTextObj = Obj.m_pTextObj;
-  CPDF_ContentMarkData* pMarkData =
-      (CPDF_ContentMarkData*)pTextObj->m_ContentMark.GetObject();
+  const CPDF_ContentMarkData* pMarkData = pTextObj->m_ContentMark.GetObject();
   if (!pMarkData)
     return FPDFText_MarkedContent::Pass;
 
   int nContentMark = pMarkData->CountItems();
   if (nContentMark < 1)
     return FPDFText_MarkedContent::Pass;
 
   CFX_WideString actText;
   FX_BOOL bExist = FALSE;
   CPDF_Dictionary* pDict = nullptr;
   int n = 0;
   for (n = 0; n < nContentMark; n++) {
-    CPDF_ContentMarkItem& item = pMarkData->GetItem(n);
+    const CPDF_ContentMarkItem& item = pMarkData->GetItem(n);
     if (item.GetParamType() == CPDF_ContentMarkItem::ParamType::None)
       continue;
     pDict = item.GetParam();
     CPDF_String* temp =
         ToString(pDict ? pDict->GetObjectBy("ActualText") : nullptr);
     if (temp) {
       bExist = TRUE;
       actText = temp->GetUnicodeText();
     }
   }
   if (!bExist)
     return FPDFText_MarkedContent::Pass;
 
   if (m_pPreTextObj) {
-    CPDF_ContentMarkData* pPreMarkData =
-        (CPDF_ContentMarkData*)m_pPreTextObj->m_ContentMark.GetObject();
+    const CPDF_ContentMarkData* pPreMarkData =
+        m_pPreTextObj->m_ContentMark.GetObject();
     if (pPreMarkData && pPreMarkData->CountItems() == n &&
         pDict == pPreMarkData->GetItem(n - 1).GetParam()) {
       return FPDFText_MarkedContent::Done;
     }
   }
   FX_STRSIZE nItems = actText.GetLength();
   if (nItems < 1)
     return FPDFText_MarkedContent::Pass;
 
   CPDF_Font* pFont = pTextObj->GetFont();
@@ skipping 17 matching lines @@
     }
   }
   if (!bExist)
     return FPDFText_MarkedContent::Done;
 
   return FPDFText_MarkedContent::Delay;
 }
 
 void CPDF_TextPage::ProcessMarkedContent(PDFTEXT_Obj Obj) {
   CPDF_TextObject* pTextObj = Obj.m_pTextObj;
-  CPDF_ContentMarkData* pMarkData =
-      (CPDF_ContentMarkData*)pTextObj->m_ContentMark.GetObject();
+  const CPDF_ContentMarkData* pMarkData = pTextObj->m_ContentMark.GetObject();
   if (!pMarkData)
     return;
 
   int nContentMark = pMarkData->CountItems();
   if (nContentMark < 1)
     return;
   CFX_WideString actText;
   CPDF_Dictionary* pDict = nullptr;
   for (int n = 0; n < nContentMark; n++) {
-    CPDF_ContentMarkItem& item = pMarkData->GetItem(n);
+    const CPDF_ContentMarkItem& item = pMarkData->GetItem(n);
     if (item.GetParamType() == CPDF_ContentMarkItem::ParamType::None)
       continue;
     pDict = item.GetParam();
     if (pDict)
       actText = pDict->GetUnicodeTextBy("ActualText");
   }
   FX_STRSIZE nItems = actText.GetLength();
   if (nItems < 1)
     return;
 
@@ skipping 1237 matching lines @@
   return index < m_LinkArray.size() ? m_LinkArray[index].m_strUrl : L"";
 }
 
 std::vector<CFX_FloatRect> CPDF_LinkExtract::GetRects(size_t index) const {
   if (index >= m_LinkArray.size())
     return std::vector<CFX_FloatRect>();
 
   return m_pTextPage->GetRectArray(m_LinkArray[index].m_Start,
                                    m_LinkArray[index].m_Count);
 }