[0.8-preview] detached not getting called when the element being removed is in the localDom of another element.

[frankiefu]

Under CustomElements polyfill (e.g. Safari, Firefox), detached is not getting called when trying to remove an element (x-foo) which is in the localDom of another element (x-app).

<script>
  Polymer({
    is: 'x-foo',
    detached: function() {
      console.log('x-foo.detached');
    }
  });
</script>

<dom-module id="x-app">
  <template>
    <x-foo id="foo"></x-foo>
  </template>
</dom-module>

<script>
  Polymer({
    is: 'x-app',
    removeFoo: function() {
      this.$.foo.remove();
    }
  });
</script>

In the above, calling removeFoo() will not trigger x-foo's detached callback.

This is because in ready.html, host is being added to the element but in CustomElements/observe.js we also use host to determine if the element is inDocument.

[sorvell]

Fixed via webcomponents/webcomponentsjs@a8ec8d6