Add CancelChannelCreation() in protocol::Session interface.

remoting/protocol/pepper_channel.h

 // Copyright (c) 2011 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_PEPPER_CHANNEL_H_
 #define REMOTING_PROTOCOL_PEPPER_CHANNEL_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 20 matching lines @@
 
   // Connect the channel using specified |config|.
   virtual void Connect(pp::Instance* pp_instance,
                        const TransportConfig& config,
                        const std::string& remote_cert) = 0;
 
   // Adds |candidate| received from the peer.
   virtual void AddRemoveCandidate(const cricket::Candidate& candidate) = 0;
 
   // Name of the channel.
-  virtual const std::string& name() = 0;
+  virtual const std::string& name() const = 0;
+
+  // returns true if the channel is already connected
+  virtual bool is_connected() const = 0;
 
  protected:
   DISALLOW_COPY_AND_ASSIGN(PepperChannel);
 };
 
 }  // namespace protocol
 }  // namespace remoting
 
 #endif  // REMOTING_PROTOCOL_PEPPER_CHANNEL_H_