Adding 'part of html' to all files which are used by dart:html.

sdk/lib/html/templates/dart2js_impl.darttemplate

Index: sdk/lib/html/templates/dart2js_impl.darttemplate
diff --git a/sdk/lib/html/templates/dart2js_impl.darttemplate b/sdk/lib/html/templates/dart2js_impl.darttemplate
index adf1cf154e26330b482869cdfd3f5c09b1ff373e..0a2e0d46b40eb223b980fc4c5f7356a87d664bdf 100644
--- a/sdk/lib/html/templates/dart2js_impl.darttemplate
+++ b/sdk/lib/html/templates/dart2js_impl.darttemplate
@@ -1,3 +1,8 @@
+// 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 html;
 
 /// @domName $DOMNAME
 class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {