Use std::map as CPDF_Dictionary's underlying store.

core/src/fpdfapi/fpdf_parser/fpdf_parser_utility.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_ext.h"
 
@@ skipping 365 matching lines @@
         } else {
           buf << pElement;
         }
       }
       buf << "]";
       break;
     }
     case PDFOBJ_DICTIONARY: {
       const CPDF_Dictionary* p = pObj->AsDictionary();
       buf << "<<";
-      FX_POSITION pos = p->GetStartPos();
-      while (pos) {
-        CFX_ByteString key;
-        CPDF_Object* pValue = p->GetNextElement(pos, key);
+      for (const auto& it : *p) {
+        const CFX_ByteString& key = it.first;
+        CPDF_Object* pValue = it.second;
         buf << "/" << PDF_NameEncode(key);
         if (pValue && pValue->GetObjNum()) {
           buf << " " << pValue->GetObjNum() << " 0 R ";
         } else {
           buf << pValue;
         }
       }
       buf << ">>";
       break;
     }
@@ skipping 53 matching lines @@
     CPDF_Object* pFound = SearchNumberNode(pKid, num);
     if (pFound) {
       return pFound;
     }
   }
   return NULL;
 }
 CPDF_Object* CPDF_NumberTree::LookupValue(int num) {
   return SearchNumberNode(m_pRoot, num);
 }