Tray elements behave appropriately on the multiple signin screen (more like lock screen)

chrome/browser/ui/ash/session_state_delegate_chromeos.h

 // Copyright (c) 2013 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_UI_ASH_SESSION_STATE_DELEGATE_CHROMEOS_H_
 #define CHROME_BROWSER_UI_ASH_SESSION_STATE_DELEGATE_CHROMEOS_H_
 
 #include "ash/session/session_state_delegate.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ skipping 34 matching lines @@
       ash::MultiProfileIndex index) const OVERRIDE;
   virtual const ash::UserInfo* GetUserInfo(
       content::BrowserContext* context) const OVERRIDE;
   virtual bool ShouldShowAvatar(aura::Window* window) const OVERRIDE;
   virtual void SwitchActiveUser(const std::string& user_id) OVERRIDE;
   virtual void CycleActiveUser(CycleUser cycle_user) OVERRIDE;
   virtual void AddSessionStateObserver(
       ash::SessionStateObserver* observer) OVERRIDE;
   virtual void RemoveSessionStateObserver(
       ash::SessionStateObserver* observer) OVERRIDE;
+  virtual void HideMultiUserSigninScreen() OVERRIDE;
 
   // chromeos::LoginState::Observer overrides.
   virtual void LoggedInStateChanged() OVERRIDE;
 
   // chromeos::UserManager::UserSessionStateObserver:
   virtual void ActiveUserChanged(const chromeos::User* active_user) OVERRIDE;
   virtual void UserAddedToSession(const chromeos::User* added_user) OVERRIDE;
 
   // chromeos::UserAddingScreen::Observer:
   virtual void OnUserAddingStarted() OVERRIDE;
@@ skipping 11 matching lines @@
   // List of observers is only used on Chrome OS for now.
   ObserverList<ash::SessionStateObserver> session_state_observer_list_;
 
   // Session state (e.g. login screen vs. user session).
   SessionState session_state_;
 
   DISALLOW_COPY_AND_ASSIGN(SessionStateDelegateChromeos);
 };
 
 #endif  // CHROME_BROWSER_UI_ASH_SESSION_STATE_DELEGATE_CHROMEOS_H_