dart:html perf optimization based on runing Dromaeo benchmarks

lib/dom/templates/html/frog/impl_HtmlElement.darttemplate

Index: lib/dom/templates/html/frog/impl_HtmlElement.darttemplate
diff --git a/lib/dom/templates/html/frog/impl_HtmlElement.darttemplate b/lib/dom/templates/html/frog/impl_HtmlElement.darttemplate
deleted file mode 100644
index aa46972cd4326558ed8641b4754f50e313df11a9..0000000000000000000000000000000000000000
--- a/lib/dom/templates/html/frog/impl_HtmlElement.darttemplate
+++ /dev/null
@@ -1,8 +0,0 @@
-// 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.
-
-class $CLASSNAME$EXTENDS$IMPLEMENTS
-    native "*IntentionallyInvalid" {
-$!MEMBERS
-}