Verify that xmpp_login specified in the config matches auth token.

remoting/jingle_glue/signal_strategy.h

Index: remoting/jingle_glue/signal_strategy.h
diff --git a/remoting/jingle_glue/signal_strategy.h b/remoting/jingle_glue/signal_strategy.h
index 89712670ae73b4733f2718bf04f686ca44e89a07..065127224180dd823fb61aa58d5b81e66ff0dc6a 100644
--- a/remoting/jingle_glue/signal_strategy.h
+++ b/remoting/jingle_glue/signal_strategy.h
@@ -30,6 +30,12 @@ class SignalStrategy {
     DISCONNECTED,
   };
 
+  enum Error {
+    OK,
+    AUTHENTICATION_FAILED,
+    NETWORK_ERROR,
+  };
+
   // Callback interface for signaling event. Event handlers are not
   // allowed to destroy SignalStrategy, but may add or remove other
   // listeners.
@@ -37,7 +43,9 @@ class SignalStrategy {
    public:
     virtual ~Listener() {}
 
-    // Called after state of the connection has changed.
+    // Called after state of the connection has changed. If the state
+    // is DISCONNECTED, then GetError() can be used to get the reason
+    // for the disconnection.
     virtual void OnSignalStrategyStateChange(State state) {}
 
     // Must return true if the stanza was handled, false
@@ -63,6 +71,9 @@ class SignalStrategy {
   // Returns current state.
   virtual State GetState() const = 0;
 
+  // Returns the last error. Set when state changes to DISCONNECT.
+  virtual Error GetError() const = 0;
+
   // Returns local JID or an empty string when not connected.
   virtual std::string GetLocalJid() const = 0;