bug: error when using with mozilla bricks (custom elements)

[tbosch]

When using zone.js together with mozilla bricks, I get the following error.
Plunker: http://plnkr.co/edit/LuKeHXiVUKRjLa3FuM5e?p=preview

Uncaught TypeError: Cannot assign to read only property 'createdCallback' of #<HTMLElement> zone.js:528
(anonymous function) zone.js:528
document.registerElement zone.js:526
xtag.register brick.js:1242
(anonymous function) brick.js:1797
(anonymous function)

[btford]

This is because brick uses property descriptors. I have a fix on the way.

[btford]

The plunker still fails with this fix... looking closer.