Optimize dartium dart:html bindings so real world application performance is acceptable. Improves d…

tools/dom/templates/html/impl/impl_Document.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;
 
 @DocsEditable()
 $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME extends Node
 {
 
@@ skipping 50 matching lines @@
   @deprecated
   bool get supportsRegister => supportsRegisterElement;
 
   @DomName('Document.createElement')
   Element createElement(String tagName, [String typeExtension]) {
 $if DART2JS
     return (typeExtension == null)
         ? _createElement_2(tagName)
         : _createElement(tagName, typeExtension);
 $else
-    var newElement = (typeExtension == null) ?
-      _blink.BlinkDocument.instance.createElement_Callback_1_(unwrap_jso(this), tagName) :
-      _blink.BlinkDocument.instance.createElement_Callback_2_(unwrap_jso(this), tagName, typeExtension);
-
-    var wrapped = js.getDartHtmlWrapperFor(newElement);  // Here's our Dart class.
-    if (wrapped != null) {
-      wrapped.blink_jsObject = newElement;
-    } else {
-      wrapped = wrap_jso(newElement);
-      if (wrapped == null) {
-        wrapped = wrap_jso_custom_element(newElement);
-      } else {
-        js.setDartHtmlWrapperFor(wrapped.blink_jsObject, wrapped);
-      }
-    }
-
-    return wrapped;
+    return (typeExtension == null) ?
+      _blink.Blink_Utils.createElement(tagName) :
+      // XXX FIX THIS CASE
+      _blink.BlinkDocument.instance.createElement_Callback_2_(this, tagName, typeExtension);
 $endif
   }
 
 $if DART2JS
   // The two-argument version of this is automatically generated, but we need to
   // omit the typeExtension if it's null on Firefox or we get an is="null" attribute.
   @DomName('Document.createElement')
   _createElement_2(String tagName) =>
       JS('Element', '#.createElement(#)', this, tagName);
 
   // The three-argument version of this is automatically generated, but we need to
   // omit the typeExtension if it's null on Firefox or we get an is="null" attribute.
   @DomName('Document.createElementNS')
   _createElementNS_2(String namespaceURI, String qualifiedName) =>
       JS('Element', '#.createElementNS(#, #)', this, namespaceURI, qualifiedName);
 
 $endif
   @DomName('Document.createElementNS')
   @DocsEditable()
   Element createElementNS(String namespaceURI, String qualifiedName, [String typeExtension]) {
 $if DART2JS
     return (typeExtension == null)
         ? _createElementNS_2(namespaceURI, qualifiedName)
         : _createElementNS(namespaceURI, qualifiedName, typeExtension);
 $else
-    var newElement = (typeExtension == null) ?
-      _blink.BlinkDocument.instance.createElementNS_Callback_2_(unwrap_jso(this), namespaceURI, qualifiedName) :
-      _blink.BlinkDocument.instance.createElementNS_Callback_3_(unwrap_jso(this), namespaceURI, qualifiedName, typeExtension);
-
-    var wrapped;
-
-    wrapped = js.getDartHtmlWrapperFor(newElement);  // Here's our Dart class.
-    if (wrapped != null) {
-      wrapped.blink_jsObject = newElement;
-    } else {
-      wrapped = wrap_jso(newElement);
-      if (wrapped == null) {
-        wrapped = wrap_jso_custom_element(newElement);
-      } else {
-        js.setDartHtmlWrapperFor(wrapped.blink_jsObject, wrapped);  // Here's our Dart class.
-      }
-    }
-
-    return wrapped;
+    return (typeExtension == null) ?
+      _blink.BlinkDocument.instance.createElementNS_Callback_2_(this, namespaceURI, qualifiedName) :
+      _blink.BlinkDocument.instance.createElementNS_Callback_3_(this, namespaceURI, qualifiedName, typeExtension);    
 $endif
   }
 
 $if DART2JS
   @DomName('Document.createNodeIterator')
   NodeIterator _createNodeIterator(Node root,
       [int whatToShow, NodeFilter filter])
       => JS('NodeIterator', '#.createNodeIterator(#, #, #, false)',
           this, root, whatToShow, filter);
 
   @DomName('Document.createTreeWalker')
   TreeWalker _createTreeWalker(Node root,
       [int whatToShow, NodeFilter filter])
       => JS('TreeWalker', '#.createTreeWalker(#, #, #, false)',
           this, root, whatToShow, filter);
 $endif
 }