DO NOT COMMIT - fn port to RenderNode, work in progress, does not work

sky/sdk/lib/framework/layout2.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import 'node.dart';
 import 'dart:sky' as sky;
 
 // ABSTRACT LAYOUT
 
 class ParentData {
@@ skipping 83 matching lines @@
     return true;
   }
   void markNeedsLayout() {
     assert(!_debugDoingLayout);
     assert(!_debugDoingPaint);
     if (_needsLayout) {
       assert(debugAncestorsAlreadyMarkedNeedsLayout());
       return;
     }
     _needsLayout = true;
-    assert(parent is RenderNode);
-    if (_relayoutSubtreeRoot != null)
+    if (_relayoutSubtreeRoot != null) {
+      assert(parent is RenderNode);
       parent.markNeedsLayout();
-    else
+    } else {
       _nodesNeedingLayout.add(this);
+    }
   }
   static void flushLayout() {
     _debugDoingLayout = true;
     List<RenderNode> dirtyNodes = _nodesNeedingLayout;
     _nodesNeedingLayout = new List<RenderNode>();
     dirtyNodes..sort((a, b) => a.depth - b.depth)..forEach((node) {
       if (node._needsLayout && node.attached)
         node._doLayout();
     });
     _debugDoingLayout = false;
@@ skipping 455 matching lines @@
   }) {
     if (newOrientation != orientation) {
       if (orientation != null && root != null)
         root.rotate(oldAngle: orientation, newAngle: newOrientation, time: timeForRotation);
       _orientation = newOrientation;
     }
     if ((newWidth != width) || (newHeight != height)) {
       _width = newWidth;
       _height = newHeight;
       relayout();
+    } else {
+      layoutDone();
     }
   }
 
   void relayout() {
     if (root != null) {
       root.layout(new BoxConstraints(
         minWidth: width,
         maxWidth: width,
         minHeight: height,
         maxHeight: height
       ));
       assert(root.width == width);
       assert(root.height == height);
     }
+    layoutDone();
   }
 
   void rotate({ int oldAngle, int newAngle, Duration time }) {
     assert(false); // nobody tells the screen to rotate, the whole rotate() dance is started from our layout()
   }
 
   bool hitTest(HitTestResult result, { double x, double y }) {
     if (x < 0.0 || x >= width || y < 0.0 || y >= height)
       return false;
     if (root != null) {
@@ skipping 281 matching lines @@
 
   void hitTestChildren(HitTestResult result, { double x, double y }) {
     defaultHitTestChildren(result, x: x, y: y);
   }
 
   void paint(RenderNodeDisplayList canvas) {
     super.paint(canvas);
     defaultPaint(canvas);
   }
 }