[Chromoting] Add DataChannelManager to manage optional incoming data channels

remoting/protocol/webrtc_data_stream_adapter.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef REMOTING_PROTOCOL_WEBRTC_DATA_STREAM_ADAPTER_H_
 #define REMOTING_PROTOCOL_WEBRTC_DATA_STREAM_ADAPTER_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 21 matching lines @@
   void Send(google::protobuf::MessageLite* message,
             const base::Closure& done) override;
 
  private:
   enum class State { CONNECTING, OPEN, CLOSED };
 
   // webrtc::DataChannelObserver interface.
   void OnStateChange() override;
   void OnMessage(const webrtc::DataBuffer& buffer) override;
 
-  void OnConnected();
-
-  void OnClosed();
-
   rtc::scoped_refptr<webrtc::DataChannelInterface> channel_;
 
   EventHandler* event_handler_ = nullptr;
 
   State state_ = State::CONNECTING;
 
   DISALLOW_COPY_AND_ASSIGN(WebrtcDataStreamAdapter);
 };
 
 }  // namespace protocol
 }  // namespace remoting
 
 #endif  // REMOTING_PROTOCOL_WEBRTC_DATA_STREAM_ADAPTER_H_