Add AUTHENTICATED session state.

remoting/protocol/session.h

Index: remoting/protocol/session.h
diff --git a/remoting/protocol/session.h b/remoting/protocol/session.h
index 4640fad7898df45f6d1754e8c4b81b516786ee8e..fa45f842afa3eb904ad5709c8ea7ecd78c86dd90 100644
--- a/remoting/protocol/session.h
+++ b/remoting/protocol/session.h
@@ -38,9 +38,12 @@ class Session : public base::NonThreadSafe {
     // session-accept.

[Wez, 2011/12/03 00:10:37]

Combining this description with those of CONNECTED and AUTHENTICATED, it's not
clear to my why the caller cares about the distinction?

[Sergey Ulanov, 2011/12/06 02:33:20]

I think we do need to distinguish between CONNECTED and AUTHENTICATED - in some
cases calling code may want to created channels in CONNECTED state to speed up
connection process.

     CONNECTING,
 
-    // Session has been accepted.
+    // Session has been accepted, but authentication is not finished yet.

[Wez, 2011/12/03 00:10:37]

nit: "... and is pending authentication."

[Sergey Ulanov, 2011/12/06 02:33:20]

Done.

     CONNECTED,
 
+    // Session has been connected and authenticated.
+    AUTHENTICATED,
+
     // Session has been closed.
     CLOSED,
 
@@ -58,7 +61,10 @@ class Session : public base::NonThreadSafe {
     CHANNEL_CONNECTION_ERROR,
   };
 
-  typedef base::Callback<void(State)> StateChangeCallback;
+  // State change callbacks are called after session state has
+  // changed. Handlers can destroy session only when |state| is set to
+  // CLOSED or FAILED.

[Wez, 2011/12/03 00:10:37]

nit: "It is not safe to destroy the session from within the handler unless
|state| is CLOSED or FAILED."

[Sergey Ulanov, 2011/12/06 02:33:20]

Done.

+  typedef base::Callback<void(State state)> StateChangeCallback;
 
   // TODO(sergeyu): Specify connection error code when channel
   // connection fails.
@@ -80,8 +86,8 @@ class Session : public base::NonThreadSafe {
   // callback is called with NULL if connection failed for any reason.
   // Ownership of the channel socket is given to the caller when the
   // callback is called. All channels must be destroyed before the
-  // session is destroyed. Can be called only when in CONNECTING or
-  // CONNECTED state.
+  // session is destroyed. Can be called only when in CONNECTING,
+  // CONNECTED or AUTHENTICATED states.
   virtual void CreateStreamChannel(
       const std::string& name, const StreamChannelCallback& callback) = 0;
   virtual void CreateDatagramChannel(