Release read buffer of QuicCryptoStream when incoming message become less frequent. Protected by --…

net/quic/core/quic_crypto_stream.cc

Index: net/quic/core/quic_crypto_stream.cc
diff --git a/net/quic/core/quic_crypto_stream.cc b/net/quic/core/quic_crypto_stream.cc
index ed8e20cc2ec17fb1ba7ed62c0b5fdf572b3ff84a..be7271c519f797009d8045845ba920c8ca22ecd3 100644
--- a/net/quic/core/quic_crypto_stream.cc
+++ b/net/quic/core/quic_crypto_stream.cc
@@ -69,6 +69,12 @@ void QuicCryptoStream::OnDataAvailable() {
       return;
     }
     sequencer()->MarkConsumed(iov.iov_len);
+    if (handshake_confirmed_ && crypto_framer_.InputBytesRemaining() == 0) {
+      // If the handshake is complete and the current message has been fully
+      // processed then no more handshake messages are likely to arrive soon
+      // so release the memory in the stream sequencer.
+      sequencer()->ReleaseBufferIfEmpty();
+    }
   }
 }