[cros Aura] Added modal container for screen lock.

ui/aura_shell/shell_window_ids.h

Index: ui/aura_shell/shell_window_ids.h
diff --git a/ui/aura_shell/shell_window_ids.h b/ui/aura_shell/shell_window_ids.h
index 2e0151a9d3a5684f58569ca48d44f063131423de..a17b6fcd294098d21ec3e4efab0b7f63a66b9f6a 100644
--- a/ui/aura_shell/shell_window_ids.h
+++ b/ui/aura_shell/shell_window_ids.h
@@ -30,11 +30,14 @@ const int kShellWindowId_ModalContainer = 4;
 // The container for the lock screen.
 const int kShellWindowId_LockScreenContainer = 5;
 
+// The container for the lock screen modal windows.
+const int kShellWindowId_LockModalContainer = 6;
+
 // The container for the status area.
-const int kShellWindowId_StatusContainer = 6;
+const int kShellWindowId_StatusContainer = 7;
 
 // The container for menus and tooltips.
-const int kShellWindowId_MenusAndTooltipsContainer = 7;
+const int kShellWindowId_MenusAndTooltipsContainer = 8;
 
 }  // namespace internal