Replace BoxDimensions with sky.Size

sky/sdk/lib/framework/fn2.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.
 
 library fn;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:mirrors';
 import 'dart:sky' as sky;
@@ skipping 932 matching lines @@
 // for now, but only for now:
 
 class RenderSolidColor extends RenderDecoratedBox {
   final sky.Size desiredSize;
   final int backgroundColor;
 
   RenderSolidColor(int backgroundColor, { this.desiredSize })
       : backgroundColor = backgroundColor,
         super(new BoxDecoration(backgroundColor: backgroundColor));
 
-  BoxDimensions getIntrinsicDimensions(BoxConstraints constraints) {
-    return new BoxDimensions.withConstraints(constraints,
-                                             width: desiredSize.width,
-                                             height: desiredSize.height);
+  sky.Size getIntrinsicDimensions(BoxConstraints constraints) {
+    return constraints.constrain(desiredSize);
   }
 
   void performLayout() {
     size = constraints.constrain(desiredSize);
   }
 
   void handlePointer(sky.PointerEvent event) {
     if (event.type == 'pointerdown')
       decoration = new BoxDecoration(backgroundColor: 0xFFFF0000);
     else if (event.type == 'pointerup')
@@ skipping 11 matching lines @@
 
   final int color;
 
   RenderSolidColor root;
   RenderSolidColor createNode() => new RenderSolidColor(color, desiredSize: new sky.Size(40.0, 130.0));
 
   static final Rectangle _emptyRectangle = new Rectangle(0);
   RenderNodeWrapper get emptyNode => _emptyRectangle;
 
 }