[Effen] Add a "parent" pointer to Node.

sky/sdk/lib/framework/layout.dart

 library layout;
 
 import 'node.dart';
 import 'dart:sky' as sky;
 import 'dart:collection';
 
 // UTILS
 
 // Bridge to legacy CSS-like style specification
 // Eventually we'll replace this with something else
@@ skipping 60 matching lines @@
   // parentData is only for use by the RenderNode that actually lays this
   // node out, and any other nodes who happen to know exactly what
   // kind of node that is.
   ParentData parentData;
   void setupPos(RenderNode child) {
     // override this to setup .parentData correctly for your class
     if (child.parentData is! ParentData)
       child.parentData = new ParentData();
   }
 
-  void setAsChild(RenderNode child) { // only for use by subclasses
+  void adoptChild(RenderNode child) { // only for use by subclasses
     // call this whenever you decide a node is a child
     assert(child != null);
     setupPos(child);
-    super.setAsChild(child);
+    super.adoptChild(child);
   }
   void dropChild(RenderNode child) { // only for use by subclasses
     assert(child != null);
     assert(child.parentData != null);
     child.parentData.detach();
     super.dropChild(child);
   }
 
 }
 
@@ skipping 46 matching lines @@
   }
 
   ChildType _firstChild;
   ChildType _lastChild;
   void add(ChildType child, { ChildType before }) {
     assert(child != this);
     assert(before != this);
     assert(child != before);
     assert(child != _firstChild);
     assert(child != _lastChild);
-    setAsChild(child);
+    adoptChild(child);
     assert(child.parentData is ParentDataType);
     assert(child.parentData.nextSibling == null);
     assert(child.parentData.previousSibling == null);
     if (before == null) {
       // append at the end (_lastChild)
       child.parentData.previousSibling = _lastChild;
       if (_lastChild != null) {
         assert(_lastChild.parentData is ParentDataType);
         _lastChild.parentData.nextSibling = child;
       }
@@ skipping 388 matching lines @@
   print(prefix + node.toString() + _attributes(node));
   var children = node.getChildNodes();
   prefix = prefix + '  ';
   for (var child in children)
     _serialiseDOM(child, prefix);
 }
 
 void dumpState() {
   _serialiseDOM(sky.document);
 }