Support transition between chrome and user mode console

ui/display/chromeos/display_configurator.h

Index: ui/display/chromeos/display_configurator.h
diff --git a/ui/display/chromeos/display_configurator.h b/ui/display/chromeos/display_configurator.h
index f4b10d0904ef92503900df84e4b489193e162be2..8ee4fdb89608be20c93edf45268b900503e4efc5 100644
--- a/ui/display/chromeos/display_configurator.h
+++ b/ui/display/chromeos/display_configurator.h
@@ -145,6 +145,14 @@ class DISPLAY_EXPORT DisplayConfigurator : public NativeDisplayObserver {
     return cached_displays_;
   }
 
+  // Called when an external process no longer needs to control the display
+  // and Chrome can take control.
+  void TakeControl();
+
+  // Called when an external process needs to control the display and thus
+  // Chrome should relinquish it.
+  void RelinquishControl();
+
   void set_state_controller(StateController* controller) {
     state_controller_ = controller;
   }