gfe-relnote: In QUIC, implement GetHandshakeState() in various handshakers. Not used yet, not protected.

GetHandshakeState() will be used to retrieve current handshake state, and handshaker is the only source of this information. But caller can choose to latch handshake state for performance purpose.

PiperOrigin-RevId: 290142490
Change-Id: I51c33c9ebcbb1ab13eddc0d86197991167642461
diff --git a/quic/core/quic_session.cc b/quic/core/quic_session.cc
index 41f8f76..8bf1410 100644
--- a/quic/core/quic_session.cc
+++ b/quic/core/quic_session.cc
@@ -1970,6 +1970,10 @@
   return !streams_waiting_for_acks_.empty();
 }
 
+HandshakeState QuicSession::GetHandshakeState() const {
+  return GetCryptoStream()->GetHandshakeState();
+}
+
 WriteStreamDataResult QuicSession::WriteStreamData(QuicStreamId id,
                                                    QuicStreamOffset offset,
                                                    QuicByteCount data_length,