Create an example app that demonstrates interactive coordination of an fn tree and a raw RenderObje…

sky/sdk/lib/widgets/basic.dart

Index: sky/sdk/lib/widgets/basic.dart
diff --git a/sky/sdk/lib/widgets/basic.dart b/sky/sdk/lib/widgets/basic.dart
index 687c116ebab036ae9de31fff5ba56148e82c476b..0e216e46d1d0dfdb93627020412aef6dc9e1b8f4 100644
--- a/sky/sdk/lib/widgets/basic.dart
+++ b/sky/sdk/lib/widgets/basic.dart
@@ -402,3 +402,27 @@ class Image extends RenderObjectWrapper {
   }
 
 }
+
+class UINodeToRenderBoxAdapter extends RenderObjectWrapper {
+
+  UINodeToRenderBoxAdapter(renderBox)

[abarth-chromium, 2015/06/16 02:32:34]

s/renderBox/RenderBox renderBox/

+    : this.renderBox = renderBox,
+      super(key: renderBox.hashCode);
+
+  RenderBox get root { RenderBox result = super.root; return result; }

[abarth-chromium, 2015/06/16 02:32:35]

RenderBox get root => super.root;

+  RenderBox createNode() => this.renderBox;
+
+  final RenderBox renderBox;
+
+  void syncRenderObject(UINode old) {
+    super.syncRenderObject(old);
+    assert(root == this.renderBox);

[abarth-chromium, 2015/06/16 02:32:35]

old.renderBox?

+  }
+
+  void insert(RenderObjectWrapper child, dynamic slot) {
+    assert(false);
+    // UINodeToRenderBoxAdapter cannot have UINode children; by
+    // definition, it is the transition out of the UINode world.
+  }
+
+}