Refactor SignalStrategy so that it can be reused for multiple connections.

remoting/jingle_glue/xmpp_signal_strategy.h

 // Copyright (c) 2011 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.
 
 // The XmppSignalStrategy encapsulates all the logic to perform the signaling
 // STUN/ICE for jingle via a direct XMPP connection.
 //
 // This class is not threadsafe.
 
 #ifndef REMOTING_JINGLE_GLUE_XMPP_SIGNAL_STRATEGY_H_
 #define REMOTING_JINGLE_GLUE_XMPP_SIGNAL_STRATEGY_H_
 
 #include "remoting/jingle_glue/signal_strategy.h"
 
 #include <vector>
 
 #include "base/compiler_specific.h"
+#include "base/observer_list.h"
 #include "third_party/libjingle/source/talk/base/sigslot.h"
 #include "third_party/libjingle/source/talk/xmpp/xmppclient.h"
 
 namespace remoting {
 
 class JingleThread;
 
 class XmppSignalStrategy : public SignalStrategy,
                            public buzz::XmppStanzaHandler,
                            public sigslot::has_slots<> {
  public:
   XmppSignalStrategy(JingleThread* thread,
                      const std::string& username,
                      const std::string& auth_token,
                      const std::string& auth_token_service);
   virtual ~XmppSignalStrategy();
 
   // SignalStrategy interface.
-  virtual void Init(StatusObserver* observer) OVERRIDE;
-  virtual void Close() OVERRIDE;
+  virtual void Connect() OVERRIDE;
+  virtual void Disconnect() OVERRIDE;
+  virtual State GetState() const OVERRIDE;
+  virtual std::string GetLocalJid() const OVERRIDE;
   virtual void AddListener(Listener* listener) OVERRIDE;
   virtual void RemoveListener(Listener* listener) OVERRIDE;
   virtual bool SendStanza(buzz::XmlElement* stanza) OVERRIDE;
   virtual std::string GetNextId() OVERRIDE;
 
   // buzz::XmppStanzaHandler interface.
   virtual bool HandleStanza(const buzz::XmlElement* stanza) OVERRIDE;
 
  private:
   void OnConnectionStateChanged(buzz::XmppEngine::State state);
   static buzz::PreXmppAuth* CreatePreXmppAuth(
       const buzz::XmppClientSettings& settings);
 
   JingleThread* thread_;
 
   std::string username_;
   std::string auth_token_;
   std::string auth_token_service_;
   buzz::XmppClient* xmpp_client_;
 
-  StatusObserver* observer_;
-  std::vector<Listener*> listeners_;
+  State state_;
 
+  ObserverList<Listener> listeners_;
 
   DISALLOW_COPY_AND_ASSIGN(XmppSignalStrategy);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_JINGLE_GLUE_XMPP_SIGNAL_STRATEGY_H_