Make the popup menu animation correct

sky/sdk/lib/framework/rendering/box.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 'dart:math' as math;
 import 'dart:sky' as sky;
 import 'dart:typed_data';
 import 'object.dart';
 import '../painting/box_painter.dart';
 import 'package:vector_math/vector_math.dart';
@@ skipping 793 matching lines @@
   void performLayout() {
     Size oldSize = size;
 
     super.performLayout();
 
     if (oldSize != size)
       callback(size);
   }
 }
 
-typedef void CustomPaintCallback(sky.Canvas canvas);
+typedef void CustomPaintCallback(sky.Canvas canvas, Size size);
 
 class RenderCustomPaint extends RenderProxyBox {
 
   RenderCustomPaint({
     CustomPaintCallback callback,
     RenderBox child
   }) : super(child) {
     assert(callback != null);
     _callback = callback;
   }
 
   CustomPaintCallback _callback;
   void set callback (CustomPaintCallback value) {
     assert(value != null || !attached);
     if (_callback == value)
       return;
     _callback = value;
     markNeedsPaint();
   }
 
   void attach() {
     assert(_callback != null);
     super.attach();
   }
 
   void paint(RenderObjectDisplayList canvas) {
     assert(_callback != null);
-    _callback(canvas);
+    _callback(canvas, size);
     super.paint(canvas);
   }
 }
 
 // RENDER VIEW LAYOUT MANAGER
 
 class ViewConstraints {
 
   const ViewConstraints({
     this.width: 0.0, this.height: 0.0, this.orientation: null
@@ skipping 97 matching lines @@
 
   void defaultPaint(RenderObjectDisplayList canvas) {
     RenderBox child = firstChild;
     while (child != null) {
       assert(child.parentData is ParentDataType);
       canvas.paintChild(child, child.parentData.position);
       child = child.parentData.nextSibling;
     }
   }
 }