Add Point.origin for new Point(0.0, 0.0)

sky/examples/raw/sector_layout.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 'package:sky/framework/app.dart';
 import 'package:sky/framework/rendering/box.dart';
 import 'package:sky/framework/rendering/object.dart';
 
@@ skipping 239 matching lines @@
   }
 
   // paint origin is 0,0 of our circle
   // each sector then knows how to paint itself at its location
   void paint(RenderObjectDisplayList canvas) {
     // TODO(ianh): avoid code duplication
     super.paint(canvas);
     RenderSector child = firstChild;
     while (child != null) {
       assert(child.parentData is SectorChildListParentData);
-      canvas.paintChild(child, new Point(0.0, 0.0));
+      canvas.paintChild(child, Point.origin);
       child = child.parentData.nextSibling;
     }
   }
 
 }
 
 class RenderSectorSlice extends RenderSectorWithChildren {
   // lays out RenderSector children in a stack
 
   RenderSectorSlice({
@@ skipping 84 matching lines @@
   }
 
   // paint origin is 0,0 of our circle
   // each sector then knows how to paint itself at its location
   void paint(RenderObjectDisplayList canvas) {
     // TODO(ianh): avoid code duplication
     super.paint(canvas);
     RenderSector child = firstChild;
     while (child != null) {
       assert(child.parentData is SectorChildListParentData);
-      canvas.paintChild(child, new Point(0.0, 0.0));
+      canvas.paintChild(child, Point.origin);
       child = child.parentData.nextSibling;
     }
   }
 
 }
 
 class RenderBoxToRenderSectorAdapter extends RenderBox {
 
   RenderBoxToRenderSectorAdapter({ double innerRadius: 0.0, RenderSector child }) :
     _innerRadius = innerRadius {
@@ skipping 123 matching lines @@
   rootCircle.add(new RenderSolidColor(const Color(0xFF0000FF), desiredDeltaTheta: kTwoPi * 0.4));
   var stack = new RenderSectorSlice(padding: 2.0);
   stack.add(new RenderSolidColor(const Color(0xFFFFFF00), desiredDeltaRadius: 20.0));
   stack.add(new RenderSolidColor(const Color(0xFFFF9000), desiredDeltaRadius: 20.0));
   stack.add(new RenderSolidColor(const Color(0xFF00FF00)));
   rootCircle.add(stack);
 
   var root = new RenderBoxToRenderSectorAdapter(innerRadius: 50.0, child: rootCircle);
   app = new AppView(root);
 }