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

core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp

Index: core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
index 264b6fb36f2e6fd386ab77a266b3c1139f21f03e..6b870e1ae2bb7c97859f297afdd7283b18abf795 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
@@ -488,10 +488,9 @@ void _PDF_ReplaceAbbr(CPDF_Object* pObj) {
   switch (pObj->GetType()) {
     case PDFOBJ_DICTIONARY: {
       CPDF_Dictionary* pDict = pObj->AsDictionary();
-      FX_POSITION pos = pDict->GetStartPos();
-      while (pos) {
-        CFX_ByteString key;
-        CPDF_Object* value = pDict->GetNextElement(pos, key);
+      for (const auto& it : *pDict) {
+        CFX_ByteString key = it.first;
+        CPDF_Object* value = it.second;
         CFX_ByteStringC fullname = _PDF_FindFullName(
             _PDF_InlineKeyAbbr, sizeof _PDF_InlineKeyAbbr / sizeof(_FX_BSTR),
             key);
@@ -552,10 +551,9 @@ void _PDF_ReplaceFull(CPDF_Object* pObj) {
   switch (pObj->GetType()) {
     case PDFOBJ_DICTIONARY: {
       CPDF_Dictionary* pDict = pObj->AsDictionary();
-      FX_POSITION pos = pDict->GetStartPos();
-      while (pos) {
-        CFX_ByteString key;
-        CPDF_Object* value = pDict->GetNextElement(pos, key);
+      for (const auto& it : *pDict) {
+        CFX_ByteString key = it.first;
+        CPDF_Object* value = it.second;
         CFX_ByteStringC abbrName = _PDF_FindAbbrName(
             _PDF_InlineKeyAbbr, sizeof(_PDF_InlineKeyAbbr) / sizeof(_FX_BSTR),
             key);