Remove CPDF_Object::GetConstString and overrides

core/fpdfdoc/doc_basic.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/fpdfapi/fpdf_parser/include/cpdf_array.h"
 #include "core/fpdfapi/fpdf_parser/include/cpdf_document.h"
 #include "core/fpdfdoc/doc_utils.h"
 #include "core/fpdfdoc/include/fpdf_doc.h"
@@ skipping 298 matching lines @@
   return result;
 #else
   return filepath;
 #endif
 }
 
 bool CPDF_FileSpec::GetFileName(CFX_WideString* csFileName) const {
   if (CPDF_Dictionary* pDict = m_pObj->AsDictionary()) {
     *csFileName = pDict->GetUnicodeTextBy("UF");
     if (csFileName->IsEmpty()) {
-      *csFileName = CFX_WideString::FromLocal(pDict->GetConstStringBy("F"));
+      *csFileName =
+          CFX_WideString::FromLocal(pDict->GetStringBy("F").AsStringC());
     }
     if (pDict->GetStringBy("FS") == "URL")
       return true;
     if (csFileName->IsEmpty()) {
       if (pDict->KeyExist("DOS")) {
         *csFileName =
             CFX_WideString::FromLocal(pDict->GetStringBy("DOS").AsStringC());
       } else if (pDict->KeyExist("Mac")) {
         *csFileName =
             CFX_WideString::FromLocal(pDict->GetStringBy("Mac").AsStringC());
@@ skipping 182 matching lines @@
   bsLbl = bsOrig;
   int nPage = FXSYS_atoi(bsLbl);
   if (nPage > 0 && nPage <= nPages) {
     return nPage;
   }
   return -1;
 }
 int32_t CPDF_PageLabel::GetPageByLabel(const CFX_WideStringC& wsLabel) const {
   return GetPageByLabel(PDF_EncodeText(wsLabel.c_str()).AsStringC());
 }