Make Quic client more memory efficient. Protected by --quic_headers_stream_release_sequencer_buffer.

net/quic/core/quic_client_session_base.h

Index: net/quic/core/quic_client_session_base.h
diff --git a/net/quic/core/quic_client_session_base.h b/net/quic/core/quic_client_session_base.h
index c8ec8bb42db2cd0bd23d84b03789477de1d1894a..f73081f72aa54fb644d26c6639343b6bda89bf47 100644
--- a/net/quic/core/quic_client_session_base.h
+++ b/net/quic/core/quic_client_session_base.h
@@ -111,6 +111,12 @@ class NET_EXPORT_PRIVATE QuicClientSessionBase
   // control accounting).
   void ResetPromised(QuicStreamId id, QuicRstStreamErrorCode error_code);
 
+  // Release headers stream's sequencer buffer if it's empty.
+  void CloseStreamInner(QuicStreamId stream_id, bool locally_reset) override;
+
+  // Returns true if there are no active requests and no promised streams.
+  bool ShouldReleaseHeadersStreamSequencerBuffer() override;
+
   size_t get_max_promises() const {
     return max_open_incoming_streams() * kMaxPromisedStreamsMultiplier;
   }