Make our raw/ tests actually check the paint output.

sky/tests/raw/render_flex.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 '../resources/third_party/unittest/unittest.dart';
 import '../resources/unit.dart';
+import '../resources/display-list.dart';
 import 'dart:sky' as sky;
 import 'package:sky/framework/app.dart';
 import 'package:sky/framework/rendering/render_block.dart';
 import 'package:sky/framework/rendering/render_box.dart';
 import 'package:sky/framework/rendering/render_flex.dart';
 
 class RenderSolidColor extends RenderDecoratedBox {
   final sky.Size desiredSize;
   final int backgroundColor;
 
@@ skipping 11 matching lines @@
   }
 
   void handlePointer(sky.PointerEvent event) {
     if (event.type == 'pointerdown')
       decoration = new BoxDecoration(backgroundColor: 0xFFFF0000);
     else if (event.type == 'pointerup')
       decoration = new BoxDecoration(backgroundColor: backgroundColor);
   }
 }
 
-AppView app;
+TestApp app;
 
 void main() {
   initUnit();
 
   test("should flex", () {
     RenderFlex flexRoot = new RenderFlex(direction: FlexDirection.Vertical);
 
     RenderDecoratedBox root = new RenderDecoratedBox(
       decoration: new BoxDecoration(backgroundColor: 0xFF000000),
       child: flexRoot
@@ skipping 30 matching lines @@
     addFlexChildSolidColor(row, 0x77FF00FF, flex: 1);
     addFlexChildSolidColor(row, 0xFF0000FF, flex: 2);
 
     var decoratedRow = new RenderDecoratedBox(
       decoration: new BoxDecoration(backgroundColor: 0xFF333333),
       child: row
     );
 
     flexRoot.add(decoratedRow);
     decoratedRow.parentData.flex = 3;
-
-    app = new AppView(root);
+    app = new TestApp(root);
 
     expect(root.size.width, equals(sky.view.width));
     expect(root.size.height, equals(sky.view.height));
     expect(renderBlock.size.width, equals(sky.view.width - 20.0));
 
   });
 }