Reduced test case

reduced_test_case.dart

  Widget build(BuildContext context) {
    return new Scaffold(
      toolBar: new ToolBar(
        backgroundColor: const Color(0xFFFFFF00)
      ),
      floatingActionButton: new FloatingActionButton(
        onPressed: () => debugDumpRenderTree(),
        child: new Container()
      ),
      body:
      new Container(
        decoration: const BoxDecoration(backgroundColor: const Color(0xFF333333)),
        child: new Block([
          new Container(
            height: 1000.0,
            decoration: const BoxDecoration(backgroundColor: const Color(0xFFFF00FF)),
            child: new PageableList<int>(
              items: [1],
              itemBuilder: (BuildContext context, int item, int index) {
                return new Container(
                  key: new Key("${item}"),
                  decoration: const BoxDecoration(backgroundColor: const Color(0xFF00FF00))
                );
              },
              itemExtent: 10.0
            )
          ),
          new Text("Hello world!")
        ])
      )
    );
  }