BackgroundFileSaver holds a reference to its nsIBackgroundFileSaverObserver
(observer). If such an observer has an enclosure that captures the
BackgroundFileSaver itself (as in test_backgroundfilesaver.js), this causes a
cycle that won't be caught by the cycle collector. Thus, we have to manually
break the cycle when we're done with the observer (in
BackgroundFileSaver::NotifySaveComplete). Note that this currently relies on the
fact that this implementation requires that Finish always be called (see remarks
in nsIBackgroundFileSaver.idl).
MozReview-Commit-ID: GOO9q2vFRso
--HG--
extra : rebase_source : f62b0ec513e0b681da3e76c0af31077d2fa03fea
extra : amend_source : 2b3a11d4b17df10705bad38e02b6ce130b456448
aa1464d4a7