Propagate connection state from networking layer to UI.

remoting/protocol/transport.h

Index: remoting/protocol/transport.h
diff --git a/remoting/protocol/transport.h b/remoting/protocol/transport.h
index 251724cda28e8a19b3bf4d1189b43e74e6f19f52..9cc013e0830f6ca1d6e8d028e5b325b9e27bac13 100644
--- a/remoting/protocol/transport.h
+++ b/remoting/protocol/transport.h
@@ -81,6 +81,14 @@ class Transport : public base::NonThreadSafe {
     virtual void OnTransportRouteChange(Transport* transport,
                                         const TransportRoute& route) = 0;
 
+    // Called when the transport inactivity state changes. When
+    // |inactive| is set to true incoming and outgoing data may be
+    // delayed until connection goes back to the active state, at
+    // which point that method is called again with |inactive| set to
+    // false. This is useful for UI indication of temporarily broken
+    // connections.
+    virtual void OnTransportInactive(Transport* transport, bool inactive) = 0;
+
     // Called when the transport is about to be deleted.
     virtual void OnTransportDeleted(Transport* transport) = 0;
   };