tree 4a82f750b2208be7798a37ebd56030cff24d38ce
parent 4fb2fe0358914027620def902338bfba2d610e86
author Matthew Dempsky <mdempsky@google.com> 1383624464 -0800
committer Matthew Dempsky <mdempsky@google.com> 1383635716 -0800

Add DOM.asOld(Element) to avoid NPEs

Calling cast() to convert a dom.Element into a user.Element can
introduce a NullPointerException when null elements are allowed.  To
remedy this and make the type safety slightly stronger, add a
DOM.asOld() helper method to cast from dom.Element to user.Element,
and replace as many calls to cast() with it as possible.

Rather than try to be clever and only convert cast()s where it would
actually make a difference, I adopted a strict rule of just converting
as many as possible.  In particular, this reverts all calls to cast()
that were introduced by d91ce52a.

Change-Id: I8c7a05be0c70d544006ae7f6356f7a05027fa1f3