Add change to dartium source file in addition to the dart2js file.

sdk/lib/html/dartium/html_dartium.dart

Index: sdk/lib/html/dartium/html_dartium.dart
diff --git a/sdk/lib/html/dartium/html_dartium.dart b/sdk/lib/html/dartium/html_dartium.dart
index 157cfbb36fd10754c6798e09cb358c9ea1c07c26..9cf898ab378ffc96acaa370448c1230bcccdc1c7 100644
--- a/sdk/lib/html/dartium/html_dartium.dart
+++ b/sdk/lib/html/dartium/html_dartium.dart
@@ -35312,13 +35312,13 @@ class KeyEvent implements KeyboardEvent {
 
   /** Accessor to provide a stream of KeyEvents on the desired target. */
   static EventStreamProvider<KeyEvent> keyDownEvent =
-    _KeyboardEventHandler('keydown');
+    new _KeyboardEventHandler('keydown');
   /** Accessor to provide a stream of KeyEvents on the desired target. */
   static EventStreamProvider<KeyEvent> keyUpEvent =
-    _KeyboardEventHandler('keyup');
+    new _KeyboardEventHandler('keyup');
   /** Accessor to provide a stream of KeyEvents on the desired target. */
   static EventStreamProvider<KeyEvent> keyPressEvent =
-    _KeyboardEventHandler('keypress');
+    new _KeyboardEventHandler('keypress');
 
   /** True if the altGraphKey is pressed during this event. */
   bool get altGraphKey => _parent.altGraphKey;