Adding "UserAddedToSession" notifier to the SessionStateObserver

chrome/browser/chromeos/login/user_manager.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 CHROME_BROWSER_CHROMEOS_LOGIN_USER_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_USER_MANAGER_H_
 
 #include <string>
 
 #include "chrome/browser/chromeos/login/user.h"
@@ skipping 22 matching lines @@
   };
 
   // TODO(nkostylev): Refactor and move this observer out of UserManager.
   // Observer interface that defines methods used to notify on user session /
   // active user state changes. Default implementation is empty.
   class UserSessionStateObserver {
    public:
     // Called when active user has changed.
     virtual void ActiveUserChanged(const User* active_user);
 
+    // Called when another user got added to the existing session.
+    virtual void UserAddedToSession(const User* added_user);
+
     // Called right before notifying on user change so that those who rely
     // on user_id hash would be accessing up-to-date value.
     virtual void ActiveUserHashChanged(const std::string& hash);
 
     // Called when UserManager finishes restoring user sessions after crash.
     virtual void PendingUserSessionsRestoreFinished();
 
    protected:
     virtual ~UserSessionStateObserver();
   };
@@ skipping 354 matching lines @@
   ScopedTestUserManager();
   ~ScopedTestUserManager();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ScopedTestUserManager);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_USER_MANAGER_H_