Refactoring: Create per-connection packet writers in QuicDispatcher.

net/tools/quic/test_tools/mock_quic_dispatcher.cc

Index: net/tools/quic/test_tools/mock_quic_dispatcher.cc
diff --git a/net/tools/quic/test_tools/mock_quic_dispatcher.cc b/net/tools/quic/test_tools/mock_quic_dispatcher.cc
index 13271ca8afc3b70e97f81a9ee29bd58036c7c03d..120c279d61f51ba07944efa4993c2c4e02b980aa 100644
--- a/net/tools/quic/test_tools/mock_quic_dispatcher.cc
+++ b/net/tools/quic/test_tools/mock_quic_dispatcher.cc
@@ -13,10 +13,12 @@ namespace test {
 MockQuicDispatcher::MockQuicDispatcher(
     const QuicConfig& config,
     const QuicCryptoServerConfig& crypto_config,
+    QuicDispatcher::PacketWriterFactory* packet_writer_factory,
     EpollServer* eps)
     : QuicDispatcher(config,
                      crypto_config,
                      QuicSupportedVersions(),
+                     packet_writer_factory,
                      eps) {}
 
 MockQuicDispatcher::~MockQuicDispatcher() {}