Gavin said in https://bugzilla.mozilla.org/show_bug.cgi?id=609890#c16
> >+ displayCachedConsoleMessages: function HUD_displayCachedConsoleMessages()
> >+ HUDService.logConsoleAPIMessage(this.hudId,
> I suppose ideally logConsoleAPIMessage would be a method of the HUD object
> rather than the service, and then displayCachedConsoleMessages could be called
> from the constructor for HeadsUpDisplay objects rather than manually after
> registerHUDReference. That probably requires some refactoring though, so no
> need to block on that.
For reference: this request also came up in bug 611032 comment 66. Also see bug 592523.