Fixed a bunch of failure cases for custom elements

tools/dom/templates/html/impl/impl_Node.darttemplate

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of $LIBRARYNAME;
 
 /**
  * Lazy implementation of the child nodes of an element that does not request
  * the actual child nodes of an element until strictly necessary greatly
  * improving performance for the typical cases where it is not required.
@@ skipping 179 matching lines @@
 
   Node operator[](int index) => _this.childNodes[index];
 
   List<Node> get rawList => _this.childNodes;
 }
 
 
 $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS {
 
   // Custom element created callback.
+$if DART2JS
   Node._created() : super._created();
+$else
+  Node._created() : super._created() {
+    // By this point blink_jsObject should be setup if it's not then we weren't
+    // called by the registerElement createdCallback - probably created() was
+    // called directly which is verboten.
+    if (this.blink_jsObject == null) {
+      throw new DomException.jsInterop("the created constructor cannot be called directly");
+    }
+  }
+$endif
 
   /**
    * A modifiable list of this node's children.
    */
   List<Node> get nodes {
     return new _ChildNodeListLazy(this);
   }
 
   set nodes(Iterable<Node> value) {
     // Copy list first since we don't want liveness during iteration.
@@ skipping 96 matching lines @@
    */
   @DomName('Node.childNodes')
   @DocsEditable()
   @Returns('NodeList')
   @Creates('NodeList')
   final List<Node> childNodes;
 
 $endif
 $!MEMBERS
 }