Make our raw/ tests actually check the paint output.

sky/tests/raw/render_flex.dart

Index: sky/tests/raw/render_flex.dart
diff --git a/sky/tests/raw/render_flex.dart b/sky/tests/raw/render_flex.dart
index 5cc95895e2ba906769b59876a9f7c801919a8a24..5a019fe8c4b430402338976fba74bbac82f54e83 100644
--- a/sky/tests/raw/render_flex.dart
+++ b/sky/tests/raw/render_flex.dart
@@ -4,6 +4,7 @@
 
 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';
@@ -35,7 +36,7 @@ class RenderSolidColor extends RenderDecoratedBox {
   }
 }
 
-AppView app;
+TestApp app;
 
 void main() {
   initUnit();
@@ -86,8 +87,7 @@ void main() {
 
     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));