Add support for multiplexed channels in remoting::protocol::Session interface.

remoting/protocol/protobuf_video_writer.h

Index: remoting/protocol/protobuf_video_writer.h
diff --git a/remoting/protocol/protobuf_video_writer.h b/remoting/protocol/protobuf_video_writer.h
index 83f551c99ca7c9502cd68f3513cdc6428d4c82a9..71dc06e2cee878d9d169ee1694030ee118af8d65 100644
--- a/remoting/protocol/protobuf_video_writer.h
+++ b/remoting/protocol/protobuf_video_writer.h
@@ -20,6 +20,7 @@ class StreamSocket;
 namespace remoting {
 namespace protocol {
 
+class ChannelFactory;
 class Session;
 
 class ProtobufVideoWriter : public VideoWriter {
@@ -41,7 +42,7 @@ class ProtobufVideoWriter : public VideoWriter {
  private:
   void OnChannelReady(scoped_ptr<net::StreamSocket> socket);
 
-  Session* session_;
+  ChannelFactory* channel_factory_;
 
   InitializedCallback initialized_callback_;