chromeos: changes how DisplayManagerObservers are notified

services/ui/ws/window_tree.h

Index: services/ui/ws/window_tree.h
diff --git a/services/ui/ws/window_tree.h b/services/ui/ws/window_tree.h
index e95912cb8fe84e25e2a9b389a8474d451dd22da8..45fef344af8c2dcd85bee2b7fee1a126fcc4d56f 100644
--- a/services/ui/ws/window_tree.h
+++ b/services/ui/ws/window_tree.h
@@ -516,6 +516,11 @@ class WindowTree : public mojom::WindowTree,
                       bool is_primary_display,
                       Id window_id,
                       const SetDisplayRootCallback& callback) override;
+  void SetDisplayConfiguration(
+      const std::vector<display::Display>& displays,
+      std::vector<ui::mojom::WmViewportMetricsPtr> viewport_metrics,
+      int64_t primary_display_id,
+      const SetDisplayConfigurationCallback& callback) override;
   void WmResponse(uint32_t change_id, bool response) override;
   void WmSetBoundsResponse(uint32_t change_id) override;
   void WmRequestClose(Id transport_window_id) override;