Create an interface for explicit notification of Dispatcher about

net/tools/quic/quic_dispatcher.h

Index: net/tools/quic/quic_dispatcher.h
diff --git a/net/tools/quic/quic_dispatcher.h b/net/tools/quic/quic_dispatcher.h
index 577b4d0dc3659332a5664077e940a4b073c6c916..47c31d213e7718c5381a8e2641a774c2bdffafdd 100644
--- a/net/tools/quic/quic_dispatcher.h
+++ b/net/tools/quic/quic_dispatcher.h
@@ -53,7 +53,8 @@ class QuicDispatcherPeer;
 class DeleteSessionsAlarm;
 class QuicEpollConnectionHelper;
 
-class QuicDispatcher : public QuicPacketWriter, public QuicSessionOwner {
+class QuicDispatcher : public QuicPacketWriter,
+                       public QuicServerSessionVisitor {
  public:
   // Ideally we'd have a linked_hash_set: the  boolean is unused.
   typedef linked_hash_map<QuicBlockedWriterInterface*, bool> WriteBlockedList;
@@ -95,9 +96,13 @@ class QuicDispatcher : public QuicPacketWriter, public QuicSessionOwner {
   // Sends ConnectionClose frames to all connected clients.
   void Shutdown();
 
+  // QuicServerSessionVisitor interface implementation:
   // Ensure that the closed connection is cleaned up asynchronously.
   virtual void OnConnectionClosed(QuicGuid guid, QuicErrorCode error) OVERRIDE;
 
+  // Queues the blocked writer for later resumption.
+  virtual void OnWriteBlocked(QuicBlockedWriterInterface* writer) OVERRIDE;
+
   typedef base::hash_map<QuicGuid, QuicSession*> SessionMap;
 
   virtual QuicSession* CreateQuicSession(