Instead of applying a transform for every RenderObject, pass down an Offset for where to paint.

sky/sdk/lib/rendering/object.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:math' as math;
 import 'dart:sky' as sky;
 import 'dart:sky' show Point, Offset, Size, Rect, Color, Paint, Path;
 
 import '../base/hit_test.dart';
 import '../base/node.dart';
@@ skipping 11 matching lines @@
   void merge(ParentData other) {
     // override this in subclasses to merge in data from other into this
     assert(other.runtimeType == this.runtimeType);
   }
   String toString() => '<none>';
 }
 
 class RenderCanvas extends sky.Canvas {
   RenderCanvas(sky.PictureRecorder recorder, Size bounds) : super(recorder, bounds);
 
-  void paintChild(RenderObject child, Point position) {
-    translate(position.x, position.y);
-    child.paint(this);
-    translate(-position.x, -position.y);
+  void paintChild(RenderObject child, Point point) {
+    child.paint(this, point.toOffset());
   }
 }
 
 abstract class Constraints {
   const Constraints();
   bool get isTight;
 }
 
 abstract class RenderObject extends AbstractNode implements HitTestTarget {
 
@@ skipping 192 matching lines @@
   }) { }
 
 
   // PAINTING
 
   static bool debugDoingPaint = false;
   void markNeedsPaint() {
     assert(!debugDoingPaint);
     scheduler.ensureVisualUpdate();
   }
-  void paint(RenderCanvas canvas) { }
+  void paint(RenderCanvas canvas, Offset offset) { }
 
 
   // EVENTS
 
   void handleEvent(sky.Event event, HitTestEntry entry) {
     // override this if you have a client, to hand it to the client
     // override this if you want to do anything with the event
   }
 
 
@@ skipping 272 matching lines @@
     int count = 1;
     ChildType child = _firstChild;
     while (child != null) {
       result += '${prefix}child ${count}: ${child.toString(prefix)}';
       count += 1;
       child = child.parentData.nextSibling;
     }
     return result;
   }
 }