Cleanup sky/sdk/examples

sky/sdk/example/widgets/spinning_mixed.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:sky' as sky;
 
 import 'package:sky/base/scheduler.dart';
 import 'package:sky/rendering/box.dart';
 import 'package:sky/rendering/flex.dart';
 import 'package:sky/rendering/sky_binding.dart';
 import 'package:sky/widgets/basic.dart';
 import 'package:sky/widgets/raised_button.dart';
 import 'package:sky/widgets/widget.dart';
 import 'package:vector_math/vector_math.dart';
 
-import '../lib/solid_color_box.dart';
-import '../../tests/resources/display_list.dart';
+import '../rendering/solid_color_box.dart';
 
 // Solid colour, RenderObject version
 void addFlexChildSolidColor(RenderFlex parent, sky.Color backgroundColor, { int flex: 0 }) {
   RenderSolidColorBox child = new RenderSolidColorBox(backgroundColor);
   parent.add(child);
   child.parentData.flex = flex;
 }
 
 // Solid colour, Widget version
 class Rectangle extends Component {
@@ skipping 26 matching lines @@
       new Rectangle(const Color(0xFFFFFF00)),
     ],
     direction: FlexDirection.vertical,
     justifyContent: FlexJustifyContent.spaceBetween
   );
 }
 
 double timeBase;
 RenderTransform transformBox;
 
-final TestRenderView tester = new TestRenderView();
-
 void rotate(double timeStamp) {
   if (timeBase == null)
     timeBase = timeStamp;
   double delta = (timeStamp - timeBase) / 1000; // radians
 
   transformBox.setIdentity();
   transformBox.translate(transformBox.size.width / 2.0, transformBox.size.height / 2.0);
   transformBox.rotateZ(delta);
   transformBox.translate(-transformBox.size.width / 2.0, -transformBox.size.height / 2.0);
 }
@@ skipping 15 matching lines @@
   addFlexChildSolidColor(flexRoot, const sky.Color(0xFFFF00FF), flex: 1);
   flexRoot.add(proxy);
   addFlexChildSolidColor(flexRoot, const sky.Color(0xFF0000FF), flex: 1);
 
   transformBox = new RenderTransform(child: flexRoot, transform: new Matrix4.identity());
   RenderPadding root = new RenderPadding(padding: new EdgeDims.all(20.0), child: transformBox);
 
   SkyBinding.instance.root = root;
   addPersistentFrameCallback(rotate);
 }