In quic, avoid infinite loop in onhandshakepacketsent if discarding initial key causes connection close (and yet another handshake packet gets sent). client only, not protected.

Uncovered in crbug/1081193.

PiperOrigin-RevId: 311385556
Change-Id: If02040ad6d47b3003c053b5b76b2d2418b8108be

quic/core/tls_client_handshaker.cc

diff --git a/quic/core/tls_client_handshaker.cc b/quic/core/tls_client_handshaker.cc
index 5c42691..0378ed0 100644
--- a/quic/core/tls_client_handshaker.cc
+++ b/quic/core/tls_client_handshaker.cc
@@ -345,9 +345,9 @@
   if (initial_keys_dropped_) {
     return;
   }
+  initial_keys_dropped_ = true;
   handshaker_delegate()->DiscardOldEncryptionKey(ENCRYPTION_INITIAL);
   handshaker_delegate()->DiscardOldDecryptionKey(ENCRYPTION_INITIAL);
-  initial_keys_dropped_ = true;
 }
 
 void TlsClientHandshaker::OnConnectionClosed(QuicErrorCode /*error*/,