lazy allocation and early release memory in QuicStreamSequencerBuffer. Protected by --quic_reduce_s…

net/quic/core/reliable_quic_stream.cc

Index: net/quic/core/reliable_quic_stream.cc
diff --git a/net/quic/core/reliable_quic_stream.cc b/net/quic/core/reliable_quic_stream.cc
index 3f1ae0a36981f98badbfa3fd84d83ad484b6222b..a1c439d16f563626645917a5fbe99938722ef3c9 100644
--- a/net/quic/core/reliable_quic_stream.cc
+++ b/net/quic/core/reliable_quic_stream.cc
@@ -353,6 +353,8 @@ void ReliableQuicStream::CloseReadSide() {
   DVLOG(1) << ENDPOINT << "Done reading from stream " << id();
 
   read_side_closed_ = true;
+  sequencer_.ReleaseBuffer();
+
   if (write_side_closed_) {
     DVLOG(1) << ENDPOINT << "Closing stream: " << id();
     session_->CloseStream(id());