Remove unused local variable.

This fails to compile in Chromium.

gfe-relnote: n/a (no functional change)
PiperOrigin-RevId: 290132011
Change-Id: I87bc8a562ca0ed1b7463cb3c6515c73e71c5cc67

quic/quic_transport/quic_transport_client_session.cc

diff --git a/quic/quic_transport/quic_transport_client_session.cc b/quic/quic_transport/quic_transport_client_session.cc
index 2a75c26..f30f97a 100644
--- a/quic/quic_transport/quic_transport_client_session.cc
+++ b/quic/quic_transport/quic_transport_client_session.cc
@@ -39,8 +39,6 @@
       const ProofVerifyDetails& /*verify_details*/) override {}
 };
 
-constexpr float kIncomingDatagramBufferSizeInCwnds = 2;
-
 }  // namespace
 
 QuicTransportClientSession::QuicTransportClientSession(