Re-enabled code to aggressively upgrade on wrap_jso

tools/dom/templates/html/dartium/html_dartium.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.
 
 // DO NOT EDIT
 // Auto-generated dart:html library.
 
 /**
  * HTML elements and other resources for web-based applications that need to
  * interact with the browser and the DOM (Document Object Model).
@@ skipping 433 matching lines @@
   try {
     if (jsObject is! js.JsObject || jsObject == null) {
       // JS Interop converted the object to a Dart class e.g., Uint8ClampedList.
       // or it's a simple type.
       return jsObject;
     }
 
     var wrapper = js.getDartHtmlWrapperFor(jsObject);
     // if we have a wrapper return the Dart instance.
     if (wrapper != null) {
+      if (wrapper.runtimeType == HtmlElement && !wrapper._isBadUpgrade) {
+        // We're a Dart instance but we need to upgrade.
+        var customElementClass = _getCustomElementType(wrapper);
+        if (customElementClass != null) {
+          var dartClass_instance;
+          try {
+            dartClass_instance = _blink.Blink_Utils.constructElement(customElementClass, jsObject);
+          } finally {
+            dartClass_instance.blink_jsObject = jsObject;
+            jsObject['dart_class'] = dartClass_instance;
+            js.setDartHtmlWrapperFor(jsObject, dartClass_instance);
+            return dartClass_instance;
+          }
+        }
+      }
+
       return wrapper;
     }
 
     if (jsObject is js.JsArray) {
       var wrappingList = new _DartHtmlWrappingList(jsObject);
       js.setDartHtmlWrapperFor(jsObject, wrappingList);
       return wrappingList;
     }
 
     // Try the most general type conversions on it.
@@ skipping 308 matching lines @@
 
 unwrap_jso(dartClass_instance) => dartClass_instance;
 wrap_jso(jsObject) => jsObject;
 make_dart_rectangle(r) => r;
 convertDartToNative_Dictionary(Map dict) => dict;
 List convertDartToNative_StringArray(List<String> input) => input;
 convertDartToNative_List(List input) => input;
 createCustomUpgrader(Type customElementClass, $this) => $this;
 
 $endif