Modal window in user session not blocks user adding screen.

ash/session_state_delegate.h

Index: ash/session_state_delegate.h
diff --git a/ash/session_state_delegate.h b/ash/session_state_delegate.h
index d3ecac8a5604f2be0fea691825910a679aa23ec7..0f2c569c5125bbea82c49e6056f9e0cb3c76f0a6 100644
--- a/ash/session_state_delegate.h
+++ b/ash/session_state_delegate.h
@@ -56,6 +56,11 @@ class ASH_EXPORT SessionStateDelegate {
   // Unlocks the screen.
   virtual void UnlockScreen() = 0;
 
+  // Returns |true| if user session blocked by some overlying UI. It can be
+  // login screen, lock screen or screen for adding users into multi-profile
+  // session.
+  virtual bool IsUserSessionBlocked() const = 0;

[sky, 2013/07/22 21:19:06]

Blocked is misleading here. In particular it makes it sound like a modal dialog
is showing, which isn't quite what you mean. Is there some other name you could
use? Maybe IsScreenLocked should return an enum?

[dzhioev (left Google), 2013/07/23 14:06:01]

'Locked' is already widely used for lock screen, e.g. we have Lock/UnlockScreen
methods. If IsScreenLocked returned enum LockScreen would receive enum as param,
but it makes no sense to call LockScreen(LOGIN_SCREEN). So I think we need some
different name. Maybe 'Hidden'?

[sky, 2013/07/23 14:34:37]

I think I like IsUserSessionBlocked better. So, stick with what you have here.

+
   // Gets the displayed name for the user with the given |index|.
   // Note that |index| can at maximum be |NumberOfLoggedInUsers() - 1|.
   virtual const base::string16 GetUserDisplayName(