Fixed suggesting adding more users into multi-profile session when we don't have more

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 31 matching lines @@
 // TODO(oshima): Replace MultiProfileIndex with BrowsreContext, bacause
 // GetUserXXX are useful for non multi profile scenario in ash_shell.
 class ASH_EXPORT SessionStateDelegate {
  public:
   // Defines the cycle direction for |CycleActiveUser|.
   enum CycleUser {
     CYCLE_TO_NEXT_USER = 0,  // Cycle to the next user.
     CYCLE_TO_PREVIOUS_USER,  // Cycle to the previous user.
   };
 
+  enum MultiProfileAddUserError {

[James Cook, 2014/09/23 16:02:12]

This is fine, but I would also be OK with a shorter name, like AddUserError and
ADD_USER_ERROR_*

[Roman Sorokin (ftl), 2014/09/24 08:30:47]

Done.

+    MULTIPROFILE_ADD_USER_ERROR_NOT_ALLOWED_PRIMARY_USER = 0,
+    MULTIPROFILE_ADD_USER_ERROR_OUT_OF_USERS,
+    MULTIPROFILE_ADD_USER_ERROR_MAXIMUM_OF_USERS_REACHED,

[James Cook, 2014/09/23 16:02:12]

nit: I would say _MAXIMUM_USERS_REACHED

[Roman Sorokin (ftl), 2014/09/24 08:30:47]

Done.

+  };
+
   // Defines session state i.e. whether session is running or not and
   // whether user session is blocked by things like multi-profile login.
   enum SessionState {
     // When primary user login UI is shown i.e. after boot or sign out,
     // no active user session exists yet.
     SESSION_STATE_LOGIN_PRIMARY = 0,
 
     // Inside user session (including lock screen),
     // no login UI (primary or multi-profiles) is shown.
     SESSION_STATE_ACTIVE,
@@ skipping 13 matching lines @@
   virtual content::BrowserContext* GetBrowserContextForWindow(
       aura::Window* window) = 0;
 
   // Returns the maximum possible number of logged in users.
   virtual int GetMaximumNumberOfLoggedInUsers() const = 0;
 
   // Returns the number of signed in users. If 0 is returned, there is either
   // no session in progress or no active user.
   virtual int NumberOfLoggedInUsers() const = 0;
 
+  // Returns true if there is possible to add more users to multiprofile
+  // session. Error is stored in |error| if it is not NULL and function
+  // returned false.
+  virtual bool CanAddUserToMultiProfile(MultiProfileAddUserError* error) const;
+
   // Returns |true| if the session has been fully started for the active user.
   // When a user becomes active, the profile and browser UI are not immediately
   // available. Only once this method starts returning |true| is the browser
   // startup complete and both profile and UI are fully available.
   virtual bool IsActiveUserSessionStarted() const = 0;
 
   // Returns true if the screen can be locked.
   virtual bool CanLockScreen() const = 0;
 
   // Returns true if the screen is currently locked.
@@ skipping 45 matching lines @@
   // Adds or removes sessions state observer.
   virtual void AddSessionStateObserver(SessionStateObserver* observer) = 0;
   virtual void RemoveSessionStateObserver(SessionStateObserver* observer) = 0;
 
   bool IsInSecondaryLoginScreen() const;
 };
 
 }  // namespace ash
 
 #endif  // ASH_SESSION_SESSION_STATE_DELEGATE_H_