As described in <https://developer.apple.com/library/mac/technotes/tn2206/>, for bundles containing a Versions directory there may be no other content at the top level of the bundle other than symlinks. Upcoming changes to code signing will prevent bundles that violate this rule from being signed.
This is primarily needed to keep nightly builds working (<rdar://problem/17921051>).
Created attachment 236557 [details]
Committed r172595: <http://trac.webkit.org/changeset/172595>