Created attachment 593150 [details] [diff] [review] rm Bug 650353 plans to make compartments and globals 1:1 (for a multitude of reasons). Unfortunately, this makes implementing the sameGroupAs optimization impossible. Fortunately, bug 720753 will make JSCompartment a lot slimmer so the optimization shouldn't matter as much. The attached patch essentially backs out bug 677294. There are no uses of sameGroupAs on mozilla-central, only the addons-sdk, so cc'ing some jetpack folks.
Comment on attachment 593150 [details] [diff] [review] rm Is it worth warning in the error console to make it easier to find uses of sameGroupAs. The Jetpack folks knew that this was coming, along with the slimmer compartments, so hopefully this shouldn't be controversial. That said, we probably shouldn't land this until we actually do slim down compartments.