Doc Theme is incompatible with Page Restrictions

When using the doc theme, if you choose Tools/Restrictions nothing happens. It seems that the AJAX request is malformed, and omits the space key. When trying in edit mode, the dialog appears, but fails when actually trying to add users/groups, for the same reason.

Additionally, when opening the Restrictions dialog from the "Restrictions" link in the page edit window, the dialog options, but none of the functionality actually works. This appears to be an additional symptom of the same problem, as the fix for the issue solves both problems.

This was fixed in 3.4 as CONF-20454

It also affects 3.3.1, but doesn't seem to be an issue in 3.3.

We should fix this before releasing 3.3.1.