Combine window.setTimeout/setInterval with Timer and Timer.repeating. Also

samples/swarm/swarm_ui_lib/layout/GridLayout.dart

Index: samples/swarm/swarm_ui_lib/layout/GridLayout.dart
diff --git a/samples/swarm/swarm_ui_lib/layout/GridLayout.dart b/samples/swarm/swarm_ui_lib/layout/GridLayout.dart
index 47c2f10011ee6f83cf638ec9a56356dee495e94d..89752a6a27ce5a4f240acf72e21d8789f5e3516e 100644
--- a/samples/swarm/swarm_ui_lib/layout/GridLayout.dart
+++ b/samples/swarm/swarm_ui_lib/layout/GridLayout.dart
@@ -101,7 +101,7 @@ class GridLayout extends ViewLayout {
   /** The main entry point for layout computation. */
   void measureLayout(Future<Size> size, Completer<bool> changed) {
     _ensureAllTracks();
-    window.setImmediate(() {
+    window.immediate.then((_) {
       _gridWidth = size.value.width;
       _gridHeight = size.value.height;