Move ScopedSetInsertion to third_party/base/stl_util.h

core/src/fpdfapi/fpdf_parser/cpdf_document.cpp

Index: core/src/fpdfapi/fpdf_parser/cpdf_document.cpp
diff --git a/core/src/fpdfapi/fpdf_parser/cpdf_document.cpp b/core/src/fpdfapi/fpdf_parser/cpdf_document.cpp
index d97d6e01ff6a574e359a9624833acbef688c4f88..e509e36382c82b3cd53f05231a6209285a04fd1f 100644
--- a/core/src/fpdfapi/fpdf_parser/cpdf_document.cpp
+++ b/core/src/fpdfapi/fpdf_parser/cpdf_document.cpp
@@ -35,7 +35,8 @@ int CountPages(CPDF_Dictionary* pPages,
     }
     if (pKid->KeyExist("Kids")) {
       // Use |visited_pages| to help detect circular references of pages.
-      ScopedSetInsertion<CPDF_Dictionary*> local_add(visited_pages, pKid);
+      pdfium::ScopedSetInsertion<CPDF_Dictionary*> local_add(visited_pages,
+                                                             pKid);
       count += CountPages(pKid, visited_pages);
     } else {
       // This page is a leaf node.