Test tools for udp proxying. This involves a few refactors of test

net/tools/quic/quic_server.cc

Index: net/tools/quic/quic_server.cc
diff --git a/net/tools/quic/quic_server.cc b/net/tools/quic/quic_server.cc
index 71fd578c23fb95b1efb45a7a3bddcb57c8f7e718..be3d9fbd128178a8161294247535f455dd3053c6 100644
--- a/net/tools/quic/quic_server.cc
+++ b/net/tools/quic/quic_server.cc
@@ -162,16 +162,20 @@ bool QuicServer::Listen(const IPEndPoint& address) {
   }
 
   epoll_server_.RegisterFD(fd_, this, kEpollFlags);
-  dispatcher_.reset(new QuicDispatcher(
-      config_,
-      crypto_config_,
-      supported_versions_,
-      &epoll_server_));
+  dispatcher_.reset(CreateQuicDispatcher());
   dispatcher_->Initialize(fd_);
 
   return true;
 }
 
+QuicDispatcher* QuicServer::CreateQuicDispatcher() {
+  return new QuicDispatcher(
+      config_,
+      crypto_config_,
+      supported_versions_,
+      &epoll_server_);
+}
+
 void QuicServer::WaitForEvents() {
   epoll_server_.WaitForEventsAndExecuteCallbacks();
 }