Remove DisplayState from the public interface for DisplayConfigurator

ash/display/display_change_observer_chromeos.h

Index: ash/display/display_change_observer_chromeos.h
diff --git a/ash/display/display_change_observer_chromeos.h b/ash/display/display_change_observer_chromeos.h
index a6a4dfd3d4776560fa2c8d5d9b549a5754397f59..d275aa18ae921f1827158a062f0b432d8ea21876 100644
--- a/ash/display/display_change_observer_chromeos.h
+++ b/ash/display/display_change_observer_chromeos.h
@@ -17,6 +17,7 @@ namespace ash {
 
 class DisplayInfo;
 struct DisplayMode;
+class DisplaySnapshot;
 
 // An object that observes changes in display configuration and
 // update DisplayManagers.
@@ -28,11 +29,11 @@ class DisplayChangeObserver : public ui::DisplayConfigurator::StateController,
   // Returns the mode list for internal display.
   ASH_EXPORT static std::vector<DisplayMode> GetInternalDisplayModeList(
       const DisplayInfo& display_info,
-      const ui::DisplayConfigurator::DisplayState& output);
+      const ui::DisplaySnapshot& output);
 
   // Returns the resolution list.
   ASH_EXPORT static std::vector<DisplayMode> GetExternalDisplayModeList(
-      const ui::DisplayConfigurator::DisplayState& output);
+      const ui::DisplaySnapshot& output);
 
   DisplayChangeObserver();
   ~DisplayChangeObserver() override;