Decouple Canvas from DisplayList and map Picture and PictureRecorder more directly to their Skia co…

sky/sdk/lib/framework/widgets/scaffold.dart

Index: sky/sdk/lib/framework/widgets/scaffold.dart
diff --git a/sky/sdk/lib/framework/widgets/scaffold.dart b/sky/sdk/lib/framework/widgets/scaffold.dart
index 5d95f6306467b6c9c5e2d00f2032b5f8324de22d..fee892e5e4ee11d7da83f8af8a53ce29879d9f59 100644
--- a/sky/sdk/lib/framework/widgets/scaffold.dart
+++ b/sky/sdk/lib/framework/widgets/scaffold.dart
@@ -5,6 +5,7 @@
 import '../rendering/box.dart';
 import '../rendering/object.dart';
 import '../theme2/view_configuration.dart';
+import 'dart:sky' as sky;
 import 'ui_node.dart';
 
 enum ScaffoldSlots {
@@ -124,12 +125,12 @@ class RenderScaffold extends RenderBox {
     }
   }
 
-  void paint(RenderObjectDisplayList canvas) {
+  void paint(sky.Canvas canvas) {
     for (ScaffoldSlots slot in [ScaffoldSlots.body, ScaffoldSlots.statusBar, ScaffoldSlots.toolbar, ScaffoldSlots.floatingActionButton, ScaffoldSlots.drawer]) {
       RenderBox box = _slots[slot];
       if (box != null) {
         assert(box.parentData is BoxParentData);
-        canvas.paintChild(box, box.parentData.position);
+        paintChild(canvas, box, box.parentData.position);
       }
     }
   }