Refactor of Authenticator to allow it to ProcessMessage asynchronously and then call a callback

remoting/protocol/negotiating_authenticator.h

Index: remoting/protocol/negotiating_authenticator.h
diff --git a/remoting/protocol/negotiating_authenticator.h b/remoting/protocol/negotiating_authenticator.h
index eded6220fe47df051aec1bf95faebe7e67767eeb..02a6301e068ad82a1c5cc9954856370d3fc75269 100644
--- a/remoting/protocol/negotiating_authenticator.h
+++ b/remoting/protocol/negotiating_authenticator.h
@@ -42,7 +42,8 @@ class NegotiatingAuthenticator : public Authenticator {
   // Authenticator interface.
   virtual State state() const OVERRIDE;
   virtual RejectionReason rejection_reason() const OVERRIDE;
-  virtual void ProcessMessage(const buzz::XmlElement* message) OVERRIDE;
+  virtual void ProcessMessage(const base::Closure& resume_callback,
+                              const buzz::XmlElement* message) OVERRIDE;
   virtual scoped_ptr<buzz::XmlElement> GetNextMessage() OVERRIDE;
   virtual scoped_ptr<ChannelAuthenticator>
       CreateChannelAuthenticator() const OVERRIDE;
@@ -52,6 +53,7 @@ class NegotiatingAuthenticator : public Authenticator {
 
   void AddMethod(const AuthenticationMethod& method);
   void CreateAuthenticator(State initial_state);
+  void UpdateState(const base::Closure& resume_callback);
 
   bool is_host_side() const;