dart-lang/js-interop — pull request #106 by a14n (2013-09-04 21:25:37+00:00)
Title: provide a way to handle elements in ShadowDom

Basically you have to bind all the `host`s of the `ShadowRoot`s to make `Element`s transferable (even in `ShadowRoot`). In Dart by calling `js.registerHost(root, host)` and in JS with `root.host = host`.