1e8a275a20
This reverts commit 560f12bb21.
modified: sdk/lib/html/dart2js/html_dart2js.dart
modified: sdk/lib/html/dartium/html_dartium.dart
modified: tests/html/element_add_test.dart
modified: tools/dom/templates/html/impl/impl_Element.darttemplate
BUG=
Review URL: https://codereview.chromium.org//1230553003 .