Add TransportContext class.

remoting/protocol/connection_to_host.h

Index: remoting/protocol/connection_to_host.h
diff --git a/remoting/protocol/connection_to_host.h b/remoting/protocol/connection_to_host.h
index ad9c8bafd30bd30cbc7399ca7ea99014757ad362..f5c8c8207f20aa95056abf06f336328d57071af3 100644
--- a/remoting/protocol/connection_to_host.h
+++ b/remoting/protocol/connection_to_host.h
@@ -27,7 +27,7 @@ class ExtensionMessage;
 class HostStub;
 class InputStub;
 class SessionConfig;
-class TransportFactory;
+class TransportContext;
 struct TransportRoute;
 class VideoStub;
 
@@ -92,7 +92,7 @@ class ConnectionToHost {
   // and must outlive the ConnectionToHost.
   // Caller must set stubs (see below) before calling Connect.
   virtual void Connect(SignalStrategy* signal_strategy,
-                       scoped_ptr<TransportFactory> transport_factory,
+                       scoped_refptr<TransportContext> transport_context,
                        scoped_ptr<Authenticator> authenticator,
                        const std::string& host_jid,
                        HostEventCallback* event_callback) = 0;