Changing window.requestLayoutFrame into a microtask API

samples/swarm/swarm_ui_lib/view/PagedViews.dart

Index: samples/swarm/swarm_ui_lib/view/PagedViews.dart
diff --git a/samples/swarm/swarm_ui_lib/view/PagedViews.dart b/samples/swarm/swarm_ui_lib/view/PagedViews.dart
index 310f554779f55417c9d2d1a9face98185101a35a..a03dd5ef25ddb7ac7500e4f6750af1d9f38164c9 100644
--- a/samples/swarm/swarm_ui_lib/view/PagedViews.dart
+++ b/samples/swarm/swarm_ui_lib/view/PagedViews.dart
@@ -135,7 +135,8 @@ class PagedColumnView extends View {
   // TODO(jmesserly): would be better to not have this code in enterDocument.
   // But we need computedStyle to read our CSS properties.
   void enterDocument() {
-    contentView.node.computedStyle.then((CssStyleDeclaration style) {
+    window.setImmediate(() {
+      var style = contentView.node.getComputedStyle();
       _computeColumnGap(style);
 
       // Trigger a fake resize event so we measure our height.
@@ -182,7 +183,7 @@ class PagedColumnView extends View {
     // The content needs to have its height explicitly set, or columns don't
     // flow to the right correctly. So we copy our own height and set the height
     // of the content.
-    window.requestLayoutFrame(() {
+    window.setImmediate(() {
       contentView.node.style.height = '${node.offsetHeight}px';
     });
     _updatePageCount(null);
@@ -190,7 +191,7 @@ class PagedColumnView extends View {
 
   bool _updatePageCount(Callback callback) {
     int pageLength = 1;
-    window.requestLayoutFrame(() {
+    window.setImmediate(() {
       if (_container.scrollWidth > _container.offsetWidth) {
         pageLength = (_container.scrollWidth / _computePageSize(_container))
             .ceil().toInt();
@@ -215,7 +216,7 @@ class PagedColumnView extends View {
   }
 
   void _onContentMoved(Event e) {
-    window.requestLayoutFrame(() {
+    window.setImmediate(() {
       num current = scroller.contentOffset.x;
       int pageSize = _computePageSize(_container);
       pages.current.value = -(current / pageSize).round().toInt();
@@ -225,7 +226,7 @@ class PagedColumnView extends View {
   void _snapToPage(Event e) {
     num current = scroller.contentOffset.x;
     num currentTarget = scroller.currentTarget.x;
-    window.requestLayoutFrame(() {
+    window.setImmediate(() {
       int pageSize = _computePageSize(_container);
       int destination;
       num currentPageNumber = -(current / pageSize).round();
@@ -277,7 +278,7 @@ class PagedColumnView extends View {
   }
 
   void _onPageSelected() {
-    window.requestLayoutFrame(() {
+    window.setImmediate(() {
       int translate = -pages.target.value * _computePageSize(_container);
       scroller.throwTo(translate, 0);
     });