Fixing broken tests because of mismatch of suppressed warnings.

sdk/lib/html/dart2js/html_dart2js.dart

 /// The Dart HTML library.
 library dart.dom.html;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:_collection-dev' hide Symbol;
 import 'dart:html_common';
 import 'dart:indexed_db';
 import 'dart:isolate';
 import 'dart:json' as json;
@@ skipping 22028 matching lines @@
       if (metaKey) {
         modifiers.push('Meta');
       }
       event._initWheelEvent(type, canBubble, cancelable, view, detail, screenX,
           screenY, clientX, clientY, button, relatedTarget, modifiers.join(' '),
           deltaX, deltaY, 0, 0);
     } else if (event._hasInitMouseScrollEvent) {
       var axis = 0;
       var detail = 0;
       if (deltaX != 0 && deltaY != 0) {
-        throw UnsupportedError(
+        throw new UnsupportedError(
             'Cannot modify deltaX and deltaY simultaneously');
       }
       if (deltaY != 0) {
         detail = deltaY;
         axis = JS('int', 'MouseScrollEvent.VERTICAL_AXIS');
       } else if (deltaX != 0) {
         detail = deltaX;
         axis = JS('int', 'MouseScrollEvent.HORIZONTAL_AXIS');
       }
       event._initMouseScrollEvent(type, canBubble, cancelable, view, detail,
@@ skipping 5878 matching lines @@
   static void _removeAllBindingsRecursively(Node node) {
     _nodeOrCustom(node).unbindAll();
     for (var c = node.$dom_firstChild; c != null; c = c.nextNode) {
       _removeAllBindingsRecursively(c);
     }
   }
 
   static void _removeChild(Node parent, Node child) {
     child._templateInstance = null;
     if (child is Element && (child as Element).isTemplate) {
+      Element childElement = child;
       // Make sure we stop observing when we remove an element.
-      var templateIterator = child._templateIterator;
+      var templateIterator = childElement._templateIterator;
       if (templateIterator != null) {
         templateIterator.abandon();
-        child._templateIterator = null;
+        childElement._templateIterator = null;
       }
     }
     child.remove();
     _removeAllBindingsRecursively(child);
   }
 }
 
 class _BindingToken {
   final String value;
   final bool isBinding;
@@ skipping 1384 matching lines @@
       _position = nextPosition;
       return true;
     }
     _current = null;
     _position = _array.length;
     return false;
   }
 
   T get current => _current;
 }