Fix the Sky tests

sky/sdk/lib/framework/rendering/object.dart

Index: sky/sdk/lib/framework/rendering/object.dart
diff --git a/sky/sdk/lib/framework/rendering/object.dart b/sky/sdk/lib/framework/rendering/object.dart
index 174b3c7c91e9fa36c92fac07064b66589c6dbaa3..34e3e89060e33a17e35d385dd7543d4f2581cdb7 100644
--- a/sky/sdk/lib/framework/rendering/object.dart
+++ b/sky/sdk/lib/framework/rendering/object.dart
@@ -119,6 +119,14 @@ abstract class RenderObject extends AbstractNode {
       scheduler.ensureVisualUpdate();
     }
   }
+  void scheduleInitialLayout() {
+    assert(attached);
+    assert(parent == null);
+    assert(_relayoutSubtreeRoot == null);
+    _relayoutSubtreeRoot = this;
+    _nodesNeedingLayout.add(this);
+    scheduler.ensureVisualUpdate();
+  }
   static void flushLayout() {
     _debugDoingLayout = true;
     List<RenderObject> dirtyNodes = _nodesNeedingLayout;