Add ContainsKey() and ContainsValue() and use them where appropriate.

core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.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_parser.h"
 
 #include "core/include/fxcrt/fx_string.h"
+#include "third_party/base/stl_util.h"
 
 namespace {
 
 const FX_DWORD kBlockSize = 1024;
 
 }  // namespace
 
 // static
 int CPDF_Object::s_nCurRefDepth = 0;
 
@@ skipping 257 matching lines @@
       FX_DWORD streamSize = acc.GetSize();
       CPDF_Dictionary* pDict = pThis->GetDict();
       if (pDict) {
         pDict = ToDictionary(pDict->CloneInternal(bDirect, visited));
       }
       return new CPDF_Stream(acc.DetachData(), streamSize, pDict);
     }
     case PDFOBJ_REFERENCE: {
       const CPDF_Reference* pRef = AsReference();
       FX_DWORD obj_num = pRef->GetRefObjNum();
-      if (bDirect && visited->find(obj_num) == visited->end()) {
+      if (bDirect && !pdfium::ContainsKey(*visited, obj_num)) {
         visited->insert(obj_num);
-        if (!pRef->GetDirect())
-          return nullptr;
-
-        return pRef->GetDirect()->CloneInternal(TRUE, visited);
+        auto* pDirect = pRef->GetDirect();
+        return pDirect ? pDirect->CloneInternal(TRUE, visited) : nullptr;
       }
       return new CPDF_Reference(pRef->m_pObjList, obj_num);
     }
   }
   return NULL;
 }
 CPDF_Object* CPDF_Object::CloneRef(CPDF_IndirectObjects* pDoc) const {
   if (m_ObjNum) {
     return new CPDF_Reference(pDoc, m_ObjNum);
   }
@@ skipping 867 matching lines @@
   }
   pObj->m_ObjNum = objnum;
   m_IndirectObjs.SetAt((void*)(uintptr_t)objnum, pObj);
   if (m_LastObjNum < objnum)
     m_LastObjNum = objnum;
   return TRUE;
 }
 FX_DWORD CPDF_IndirectObjects::GetLastObjNum() const {
   return m_LastObjNum;
 }