Comment 27 for bug 194573

By the fix of bug 520417, the wav file playing is executed on another thread. However, canberra still plays the system event sound (e.g., popup a menu sound, open a dialog sound) on main thread. But we don't find any problems by this. If you have problems, please file a new bug and cc me. The canberra implementation was implemented in gecko 1.9.1, so, it's not a scope of this bug.