[Sync] Propagate XMPP auth errors to SyncNotifierObservers

jingle/notifier/communicator/single_login_attempt.h

 // Copyright (c) 2012 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 JINGLE_NOTIFIER_COMMUNICATOR_SINGLE_LOGIN_ATTEMPT_H_
 #define JINGLE_NOTIFIER_COMMUNICATOR_SINGLE_LOGIN_ATTEMPT_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "jingle/notifier/base/xmpp_connection.h"
 #include "jingle/notifier/communicator/connection_settings.h"
 #include "jingle/notifier/communicator/login_settings.h"
 #include "talk/xmpp/xmppengine.h"
 
 namespace buzz {
 class XmppTaskParentInterface;
 }  // namespace buzz
 
 namespace notifier {
 
 struct ServerInformation;
 
 // Handles all of the aspects of a single login attempt.  By
 // containing this within one class, when another login attempt is
 // made, this class can be destroyed to immediately stop the previous
 // login attempt.
 class SingleLoginAttempt : public XmppConnection::Delegate {
  public:
+  // At most one delegate method will be called, depending on the
+  // result of the login attempt.  After the delegate method is
+  // called, this class won't do anything anymore until it is
+  // destroyed, at which point it will disconnect if necessary.
   class Delegate {
    public:
+    // Called when the login attempt is successful.
     virtual void OnConnect(
         base::WeakPtr<buzz::XmppTaskParentInterface> base_task) = 0;
-    virtual void OnNeedReconnect() = 0;
+
+    // Called when the server responds with a redirect.  A new login
+    // attempt should be made to the given redirect server.
     virtual void OnRedirect(const ServerInformation& redirect_server) = 0;
 
+    // Called when a server rejects the client's login credentials.  A
+    // new login attempt should be made once the client provides new
+    // credentials.
+    virtual void OnCredentialsRejected() = 0;
+
+    // Called when no server could be logged into for reasons other
+    // than redirection or rejected credentials.  A new login attempt
+    // may be created, but it should be done with exponential backoff.
+    virtual void OnSettingsExhausted() = 0;
+
    protected:
     virtual ~Delegate();
   };
 
   // Does not take ownership of |delegate|, which must not be NULL.
   SingleLoginAttempt(const LoginSettings& login_settings, Delegate* delegate);
 
   virtual ~SingleLoginAttempt();
 
   // XmppConnection::Delegate implementation.
@@ skipping 11 matching lines @@
   const ConnectionSettingsList settings_list_;
   ConnectionSettingsList::const_iterator current_settings_;
   scoped_ptr<XmppConnection> xmpp_connection_;
 
   DISALLOW_COPY_AND_ASSIGN(SingleLoginAttempt);
 };
 
 }  // namespace notifier
 
 #endif  // JINGLE_NOTIFIER_COMMUNICATOR_SINGLE_LOGIN_ATTEMPT_H_