Correct the way to count pages and to avoid infinite loop

core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp

Index: core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
index 6f0fc76fc02f5fcbf868bdeeaf759dcdbc97752a..03bc9aec58665ca7447938c25956de61995fe52f 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
@@ -36,20 +36,6 @@ struct SearchTagRecord {
   FX_DWORD m_Offset;
 };
 
-template <typename T>
-class ScopedSetInsertion {
- public:
-  ScopedSetInsertion(std::set<T>* org_set, T elem)
-      : m_Set(org_set), m_Entry(elem) {
-    m_Set->insert(m_Entry);
-  }
-  ~ScopedSetInsertion() { m_Set->erase(m_Entry); }
-
- private:
-  std::set<T>* const m_Set;
-  const T m_Entry;
-};
-
 int CompareFileSize(const void* p1, const void* p2) {
   return *(FX_FILESIZE*)p1 - *(FX_FILESIZE*)p2;
 }