Wrap sync callback for the resize event in a `$timeout` so that it
gets called asyncronously. Fixes error where `$apply` was geting
called before previous `$apply` call finished. Angular allows only
one `$apply` call at a time.
See Angular.js reference.
> [Error: $rootScope:inprog](https://docs.angularjs.org/error/$rootScope/inprog)
Fixes:
> *Error* ldn/angular in O/<
> error[$rootScope:inprog] http://errors.angularjs.org/1.5.3/$rootScope/inprog?p0=%24digest
Likely fixes other errors we're seeing related to resize events
such as
> *ReferenceError<unknown module>* in onresize
> Can't find variable: tree
