Refactoring: Create per-connection packet writers in QuicDispatcher.

net/quic/quic_per_connection_packet_writer.h

Index: net/quic/quic_per_connection_packet_writer.h
diff --git a/net/quic/quic_per_connection_packet_writer.h b/net/quic/quic_per_connection_packet_writer.h
index 96a37b61d6fe18d02638b04e1b5df298e76252e9..bf72b0f0d4ad654bee708c535cab46c077e6352f 100644
--- a/net/quic/quic_per_connection_packet_writer.h
+++ b/net/quic/quic_per_connection_packet_writer.h
@@ -21,14 +21,15 @@ class QuicServerPacketWriter;
 // writes to the shared QuicServerPacketWriter complete.
 // This class is necessary because multiple connections can share the same
 // QuicServerPacketWriter, so it has no way to know which connection to notify.
-// TODO(dmz) Try to merge with Chrome's default packet writer
 class QuicPerConnectionPacketWriter : public QuicPacketWriter {
  public:
-  QuicPerConnectionPacketWriter(QuicServerPacketWriter* writer);
+  // Does not take ownership of |shared_writer| or |connection|.
+  QuicPerConnectionPacketWriter(QuicServerPacketWriter* shared_writer,
+                                QuicConnection* connection);
   virtual ~QuicPerConnectionPacketWriter();
 
-  // Set the connection to notify after writes complete.
-  void set_connection(QuicConnection* connection) { connection_ = connection; }
+  QuicPacketWriter* shared_writer() const;
+  QuicConnection* connection() const { return connection_; }
 
   // QuicPacketWriter
   virtual WriteResult WritePacket(const char* buffer,
@@ -43,8 +44,8 @@ class QuicPerConnectionPacketWriter : public QuicPacketWriter {
   void OnWriteComplete(WriteResult result);
 
   base::WeakPtrFactory<QuicPerConnectionPacketWriter> weak_factory_;
-  QuicServerPacketWriter* writer_;  // Not owned.
-  QuicConnection* connection_;
+  QuicServerPacketWriter* shared_writer_;  // Not owned.
+  QuicConnection* connection_;  // Not owned.
 
   DISALLOW_COPY_AND_ASSIGN(QuicPerConnectionPacketWriter);
 };