Make QuicPacketWriter keep track of socket writability; expose the

net/tools/quic/test_tools/quic_dispatcher_peer.cc

Index: net/tools/quic/test_tools/quic_dispatcher_peer.cc
diff --git a/net/tools/quic/test_tools/quic_dispatcher_peer.cc b/net/tools/quic/test_tools/quic_dispatcher_peer.cc
index c96eafd57e5f4ae159c3a4124720de87b4f90240..03324a0b956031e57ab096fc0d2950feb0985dd3 100644
--- a/net/tools/quic/test_tools/quic_dispatcher_peer.cc
+++ b/net/tools/quic/test_tools/quic_dispatcher_peer.cc
@@ -4,6 +4,7 @@
 
 #include "net/tools/quic/test_tools/quic_dispatcher_peer.h"
 
+#include "net/quic/quic_default_packet_writer.h"
 #include "net/tools/quic/quic_dispatcher.h"
 
 using net::test::QuicTestWriter;
@@ -20,11 +21,6 @@ void QuicDispatcherPeer::SetTimeWaitListManager(
 }
 
 // static
-void QuicDispatcherPeer::SetWriteBlocked(QuicDispatcher* dispatcher) {
-  dispatcher->write_blocked_ = true;
-}
-
-// static
 void QuicDispatcherPeer::UseWriter(QuicDispatcher* dispatcher,
                                    QuicTestWriter* writer) {
   writer->set_writer(dispatcher->writer_.release());