Bug 1013972 - Make nsJSObjectWrapper::mJSObj a PersistentRooted. r=bsmedberg, a=bustage
Bug 1007223 - Follow-up: Fix the media decoding test, and also ensure that we're freeing the right buffer. r=Waldo, a=bustage

Note that I am not fixing the SyncDecodeMedia case to not leak, because that
code is disabled, and has been removed from later versions.