Type extension elements lose styling under polyfill

[ebidel]

The polyfill wraps scoped styles with the element name, but it doesn't do the same for type extension custom elements:

<element name="x-li" extends="li">
<template>
  <style>
    @host {
      * { list-style: none; display: block;}
    } 
    hgroup { color: red; }
  </style>
  <hgroup><content></content></hgroup>
</template>
<script>
  Polymer.register(this);
</script>
</element>

<li is="x-li">I should be red</x-li>

In Safari, the text is black. Chrome Canary, it's red.

http://jsbin.com/alecek/3/edit

cc @sorvell

[sorvell]

Acknowledged. This is a bug.... on it.

[sorvell]

Fixed by 63a1e0d