Example showing alternate async measurement solution

client/layout/ViewLayout.dart

Index: client/layout/ViewLayout.dart
diff --git a/client/layout/ViewLayout.dart b/client/layout/ViewLayout.dart
index a19c64fe4f3bdffe44379187ba48755b7f5a83d1..b79ad29b77df456c7d16c5a95560e79c44203c5f 100644
--- a/client/layout/ViewLayout.dart
+++ b/client/layout/ViewLayout.dart
@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
@@ -27,7 +27,7 @@ interface Positionable {
 class LayoutParams {
   // TODO(jmesserly): should be const, but there's a bug in DartC preventing us
   // from calling "window." in an initializer. See b/5332777
-  Future<CSSStyleDeclaration> style;
+  CSSStyleDeclaration style;
 
   int get layer() => 0;
 
@@ -71,7 +71,8 @@ class ViewLayout {
    * to determine how this view should be laid out.
    */
   LayoutParams layoutParams;
-  Future<ElementRect> _cachedViewRect;
+  int _currentWidth;
+  int _currentHeight;
 
   /** The view that this layout belongs to. */
   final Positionable view;
@@ -102,19 +103,17 @@ class ViewLayout {
     return view.customStyle['display'] == "-dart-grid";
   }
 
-  CSSStyleDeclaration get _style() => layoutParams.style.value;
+  CSSStyleDeclaration get _style() => layoutParams.style;
 
   void cacheExistingBrowserLayout() {
-    _cachedViewRect = view.node.rect;
+    assert(window.inMeasurementFrame);
+    final rect = view.node.rect.offset;
+    _currentWidth = rect.width;
+    _currentHeight = rect.height;
   }
 
-  int get currentWidth() {
-    return _cachedViewRect.value.offset.width;
-  }
-
-  int get currentHeight() {
-    return _cachedViewRect.value.offset.height;
-  }
+  int get currentWidth() => _currentWidth;
+  int get currentHeight() => _currentHeight;
 
   int get borderLeftWidth() => _toPixels(_style.borderLeftWidth);
   int get borderTopWidth() => _toPixels(_style.borderTopWidth);
@@ -124,7 +123,7 @@ class ViewLayout {
   int get borderHeight() => borderTopWidth + borderBottomWidth;
 
   /** Implements the custom layout computation. */
-  void measureLayout(Future<Size> size, Completer<bool> changed) {
+  bool measureLayout(int width, int height) {
   }
 
   /**
@@ -140,13 +139,12 @@ class ViewLayout {
     // Note: we need to save the client height
     _measuredWidth = width - borderWidth;
     _measuredHeight = height - borderHeight;
-    final completer = new Completer<Size>();
-    completer.complete(new Size(_measuredWidth, _measuredHeight));
-    measureLayout(completer.future, null);
+    measureLayout(_measuredWidth, _measuredHeight);
   }
 
   /** Applies the layout to the node. */
   void applyLayout() {
+    assert(!window.inMeasurementFrame);
     if (_measuredLeft != null) {
       // TODO(jmesserly): benchmark the performance of this DOM interaction
       final style = view.node.style;
@@ -188,7 +186,7 @@ class ViewLayout {
   }
 
   int measureWidth(ViewLayout parent, ContentSizeMode mode) {
-    final style = layoutParams.style.value;
+    final style = layoutParams.style;
     switch (mode) {
       case ContentSizeMode.MIN:
         return _styleToPixels(
@@ -201,7 +199,7 @@ class ViewLayout {
   }
 
   int measureHeight(ViewLayout parent, ContentSizeMode mode) {
-    final style = layoutParams.style.value;
+    final style = layoutParams.style;
     switch (mode) {
       case ContentSizeMode.MIN:
         return _styleToPixels(