Providing more information on why certain users can't be added to multi-profile

ash/session/session_state_delegate.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 ASH_SESSION_SESSION_STATE_DELEGATE_H_
 #define ASH_SESSION_SESSION_STATE_DELEGATE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 116 matching lines @@
   virtual bool ShouldShowAvatar(aura::Window* window) const = 0;
 
   // Switches to another active user with |user_id|
   // (if that user has already signed in).
   virtual void SwitchActiveUser(const std::string& user_id) = 0;
 
   // Switches the active user to the next or previous user, with the same
   // ordering as GetLoggedInUsers.
   virtual void CycleActiveUser(CycleUser cycle_user) = 0;
 
+  // Returns true if primary user policy does not forbid multiple signin.
+  virtual bool IsMultiProfileAllowedByPrimaryUserPolicy() const = 0;
+
   // Adds or removes sessions state observer.
   virtual void AddSessionStateObserver(SessionStateObserver* observer) = 0;
   virtual void RemoveSessionStateObserver(SessionStateObserver* observer) = 0;
 };
 
 }  // namespace ash
 
 #endif  // ASH_SESSION_SESSION_STATE_DELEGATE_H_