Unwrapped dom-if causes DOMException

[Sleeckx]

The following case throws a DOMException: NotFoundError: Failed to execute 'insertBefore' on 'Node': The node before which the new node is to be inserted is not a child of this node.

http://jsbin.com/gujenocexo/2/edit?html,output

Wrapping the dom-if template in a div fixes the error.

Could this be related to #1631?

[sorvell]

There's a bug here, but the test case should define x-inner before x-outer. Doing so avoids the issue:

http://jsbin.com/gibewu/2/edit

[sorvell]

Fixed in branch, see: http://jsbin.com/haseju/2/edit