Remove spurious print that was causing test failures.

sky/sdk/lib/widgets/widget.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:async';
 import 'dart:collection';
 import 'dart:mirrors';
 import 'dart:sky' as sky;
 
 import '../app/view.dart';
@@ skipping 485 matching lines @@
   void _sync(Widget old, dynamic slot) {
     // TODO(abarth): We should split RenderObjectWrapper into two pieces so that
     //               RenderViewObject doesn't need to inherit all this code it
     //               doesn't need.
     assert(parent != null || this is RenderViewWrapper);
     if (old == null) {
       _root = createNode();
       _ancestor = findAncestor(RenderObjectWrapper);
       if (_ancestor is RenderObjectWrapper)
         _ancestor.insert(this, slot);
-      else
-        print("$this has no ancestor");
     } else {
       _root = old.root;
       _ancestor = old._ancestor;
     }
     assert(_root == root); // in case a subclass reintroduces it
     assert(root != null);
     assert(mounted);
     _nodeMap[root] = this;
     syncRenderObject(old);
   }
@@ skipping 363 matching lines @@
     if (root.parent == null) {
       // we haven't attached it yet
       assert(_container.child == null);
       _container.child = root;
     }
     assert(root.parent == _container);
   }
 
   Widget build() => builder();
 }