Adds plumbing for always requiring handshake confirmation in QUIC.

net/quic/quic_stream_factory.cc

Index: net/quic/quic_stream_factory.cc
diff --git a/net/quic/quic_stream_factory.cc b/net/quic/quic_stream_factory.cc
index 003d17fd2cd8a87dfc828b3c794149f1674d5441..fcdb2d15414dbb46e247a8a2fbac1ea0f96984ff 100644
--- a/net/quic/quic_stream_factory.cc
+++ b/net/quic/quic_stream_factory.cc
@@ -481,6 +481,7 @@ QuicStreamFactory::QuicStreamFactory(
     const QuicVersionVector& supported_versions,
     bool enable_port_selection,
     bool enable_time_based_loss_detection,
+    bool always_require_handshake_confirmation,
     const QuicTagVector& connection_options)
     : require_confirmation_(true),
       host_resolver_(host_resolver),
@@ -496,6 +497,8 @@ QuicStreamFactory::QuicStreamFactory(
                                    connection_options)),
       supported_versions_(supported_versions),
       enable_port_selection_(enable_port_selection),
+      always_require_handshake_confirmation_(
+          always_require_handshake_confirmation),
       port_seed_(random_generator_->RandUint64()),
       weak_factory_(this) {
   DCHECK(transport_security_state_);