Refactoring: Create per-connection packet writers in QuicDispatcher.

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 ea30b2e16e087c9c686e53ac1e0c9b936b17ffe7..040c563b0a0fe0cf407d3a94dbf1052ac76a3597 100644
--- a/net/quic/quic_stream_factory.cc
+++ b/net/quic/quic_stream_factory.cc
@@ -100,6 +100,26 @@ QuicConfig InitializeQuicConfig(bool enable_pacing,
   return config;
 }
 
+class ClientPacketWriterFactory : public QuicConnection::PacketWriterFactory {

[wtc, 2014/08/13 21:01:34]

Note: I picked the "ClientPacketWriterFactory" name temporarily. Can you suggest
a better name? Perhaps "ChromiumPacketWriterFactory"? Or do you think
"ClientPacketWriterFactory" is a fine name?

[dmz, 2014/08/14 17:22:42]

I probably would have gone with DefaultPacketWriterFactory, but I think
ClientPacketWriterFactory is perfectly good. 

[wtc, 2014/08/14 20:05:00]

Ah, I now also prefer "Default" because this factory creates
QuicDefaultPacketWriter. Can you make this change?

[dmz, 2014/08/14 21:24:51]

Done.

+ public:
+  explicit ClientPacketWriterFactory(DatagramClientSocket* socket)
+      : socket_(socket) {}
+  virtual ~ClientPacketWriterFactory() {}
+
+  virtual QuicPacketWriter* Create(QuicConnection* connection) const OVERRIDE;
+
+ private:
+  DatagramClientSocket* socket_;
+};
+
+QuicPacketWriter* ClientPacketWriterFactory::Create(
+    QuicConnection* connection) const {
+  scoped_ptr<QuicDefaultPacketWriter> writer(
+      new QuicDefaultPacketWriter(socket_));
+  writer->SetConnection(connection);
+  return writer.release();
+}
+
 }  // namespace
 
 QuicStreamFactory::IpAliasKey::IpAliasKey() {}
@@ -822,8 +842,7 @@ int QuicStreamFactory::CreateSession(
     return rv;
   }
 
-  scoped_ptr<QuicDefaultPacketWriter> writer(
-      new QuicDefaultPacketWriter(socket.get()));
+  ClientPacketWriterFactory packet_writer_factory(socket.get());
 
   if (!helper_.get()) {
     helper_.reset(new QuicConnectionHelper(
@@ -834,11 +853,10 @@ int QuicStreamFactory::CreateSession(
   QuicConnection* connection = new QuicConnection(connection_id,
                                                   addr,
                                                   helper_.get(),
-                                                  writer.get(),
-                                                  false  /* owns_writer */,
+                                                  packet_writer_factory,
+                                                  true  /* owns_writer */,
                                                   false  /* is_server */,
                                                   supported_versions_);
-  writer->SetConnection(connection);
   connection->set_max_packet_length(max_packet_length_);
 
   InitializeCachedStateInCryptoConfig(server_id, server_info);
@@ -860,7 +878,7 @@ int QuicStreamFactory::CreateSession(
   }
 
   *session = new QuicClientSession(
-      connection, socket.Pass(), writer.Pass(), this,
+      connection, socket.Pass(), this,
       quic_crypto_client_stream_factory_, server_info.Pass(), server_id,
       config, &crypto_config_,
       base::MessageLoop::current()->message_loop_proxy().get(),