Similar to bug 766448, method calls for the new bindings (bug 747290) require JSJitInfo feed-through.
Created attachment 644078 [details] [diff] [review]
Applies on top of patch in bug 766448
Comment on attachment 644078 [details] [diff] [review]
Looks good. If you haven't already, I'd be sure to try (on all platforms, since iirc, there is some windows-only JSAPI use...).