Add CancelChannelCreation() in protocol::Session interface.

remoting/protocol/session.h

Index: remoting/protocol/session.h
diff --git a/remoting/protocol/session.h b/remoting/protocol/session.h
index e0a91a00585a7b3a1ee1ab48c1857ca8de7fbc2c..1bbac41d58bfcbfad67b3c2a5a4753329d4ad1e4 100644
--- a/remoting/protocol/session.h
+++ b/remoting/protocol/session.h
@@ -90,6 +90,12 @@ class Session : public base::NonThreadSafe {
   virtual void CreateDatagramChannel(
       const std::string& name, const DatagramChannelCallback& callback) = 0;
 
+  // Cancels creation of the channel |name| for previous
+  // CreateStreamChannel() and CreateDatagramChannel() calls. Can be

[Wez, 2011/11/15 22:29:13]

Wording is a little confusing.  I'd suggest:

"Cancels a pending CreateStreamChannel() or CreateDatagramChannel() operation
for the named channel.  If the channel creation already completed then
cancelling it has no effect."

Except that, looking at the Pepper implementation of CancelChannelCreation(), I
think it actually tears down the channel, doesn't it?

[Sergey Ulanov, 2011/11/16 00:01:33]

Done. Thanks for suggestion.
It tears it down only when it is not connected, i.e. is_connected()==false.

+  // called to cancel channel creation before it is finished. Call is
+  // no-op if the channel is not being created.
+  virtual void CancelChannelCreation(const std::string& name) = 0;
+
   // TODO(sergeyu): Remove these methods, and use CreateChannel()
   // instead.
   virtual net::Socket* control_channel() = 0;