Desktop equivalent of Bug 963448.
Done, 'cos this was trivial. https://hg.mozilla.org/integration/fx-team/rev/825842a7c68d
Created attachment 8373800 [details] [diff] [review] Patch for uplift. [Approval Request Comment] Bug caused by (feature/regressing bug #): None. (Part of FxA Sync work.) User impact if declined: Sync will lie about its supported versions in 29 and higher. Testing completed (on m-c, etc.): Trivial change. xpcshell tests pass. Risk to taking this patch (and alternatives if risky): None. String or IDL/UUID changes made by this patch: None.