Sharing: Apply style changes to hidden items

Before:
![2014-09-12 21 41 32](https://cloud.githubusercontent.com/assets/3660715/4249743/3188d746-3a7b-11e4-917c-ee26a58f41f8.png)

After:
![2014-09-12 21 43 04](https://cloud.githubusercontent.com/assets/3660715/4249745/33ec5512-3a7b-11e4-9190-314c67480eba.png)

In sharing preview, hidden sharing items doesn't have correct class names.