Removes an unused member and constructor/destructor definitions from HpackDecoderDynamicTable.

Protected by refactoring, no functional change.

PiperOrigin-RevId: 839769004

quiche/http2/hpack/decoder/hpack_decoder_tables.cc

diff --git a/quiche/http2/hpack/decoder/hpack_decoder_tables.cc b/quiche/http2/hpack/decoder/hpack_decoder_tables.cc
index 65f7c05..1fc505f 100644
--- a/quiche/http2/hpack/decoder/hpack_decoder_tables.cc
+++ b/quiche/http2/hpack/decoder/hpack_decoder_tables.cc
@@ -71,10 +71,6 @@
   return nullptr;
 }
 
-HpackDecoderDynamicTable::HpackDecoderDynamicTable()
-    : insert_count_(kFirstDynamicTableIndex - 1) {}
-HpackDecoderDynamicTable::~HpackDecoderDynamicTable() = default;
-
 void HpackDecoderDynamicTable::DynamicTableSizeUpdate(size_t size_limit) {
   QUICHE_DVLOG(3) << "HpackDecoderDynamicTable::DynamicTableSizeUpdate "
                   << size_limit;
@@ -99,7 +95,6 @@
     current_size_ = 0;
     return;
   }
-  ++insert_count_;
   size_t insert_limit = size_limit_ - entry_size;
   EnsureSizeNoMoreThan(insert_limit);
   table_.push_front(std::move(entry));

quiche/http2/hpack/decoder/hpack_decoder_tables.h

diff --git a/quiche/http2/hpack/decoder/hpack_decoder_tables.h b/quiche/http2/hpack/decoder/hpack_decoder_tables.h
index 7266d2b..c98064c 100644
--- a/quiche/http2/hpack/decoder/hpack_decoder_tables.h
+++ b/quiche/http2/hpack/decoder/hpack_decoder_tables.h
@@ -75,8 +75,7 @@
 //   http://httpwg.org/specs/rfc7541.html#dynamic.table.management
 class QUICHE_EXPORT HpackDecoderDynamicTable {
  public:
-  HpackDecoderDynamicTable();
-  ~HpackDecoderDynamicTable();
+  HpackDecoderDynamicTable() = default;
 
   HpackDecoderDynamicTable(const HpackDecoderDynamicTable&) = delete;
   HpackDecoderDynamicTable& operator=(const HpackDecoderDynamicTable&) = delete;
@@ -114,10 +113,6 @@
   size_t size_limit_ = Http2SettingsInfo::DefaultHeaderTableSize();
 
   size_t current_size_ = 0;
-
-  // insert_count_ and debug_listener_ are used by a QUIC experiment; remove
-  // when the experiment is done.
-  size_t insert_count_;
 };
 
 class QUICHE_EXPORT HpackDecoderTables {