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

fpdfsdk/src/fpdf_transformpage.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 "public/fpdf_transformpage.h"
 
 #include "fpdfsdk/include/fsdk_define.h"
 
@@ skipping 142 matching lines @@
                                  pDoc->AddIndirectObject(pContentArray));
       }
     }
   }
 
   // Need to transform the patterns as well.
   CPDF_Dictionary* pRes = pPageDic->GetDict("Resources");
   if (pRes) {
     CPDF_Dictionary* pPattenDict = pRes->GetDict("Pattern");
     if (pPattenDict) {
-      FX_POSITION pos = pPattenDict->GetStartPos();
-      while (pos) {
-        CPDF_Dictionary* pDict = nullptr;
-        CFX_ByteString key;
-        CPDF_Object* pObj = pPattenDict->GetNextElement(pos, key);
+      for (const auto& it : *pPattenDict) {
+        CPDF_Object* pObj = it.second;
         if (pObj->IsReference())
           pObj = pObj->GetDirect();
 
+        CPDF_Dictionary* pDict = nullptr;
         if (pObj->IsDictionary())
           pDict = pObj->AsDictionary();
         else if (CPDF_Stream* pStream = pObj->AsStream())
           pDict = pStream->GetDict();
         else
           continue;
 
         CFX_Matrix m = pDict->GetMatrix("Matrix");
         CFX_Matrix t = *(CFX_Matrix*)matrix;
         m.Concat(t);
@@ skipping 135 matching lines @@
       } else if (pDirectObj->IsStream()) {
         pContentArray = new CPDF_Array();
         pContentArray->AddReference(pDoc, pStream->GetObjNum());
         pContentArray->AddReference(pDoc, pDirectObj->GetObjNum());
         pPageDic->SetAtReference("Contents", pDoc,
                                  pDoc->AddIndirectObject(pContentArray));
       }
     }
   }
 }