With the patch for bug 767647 we stopped invalidating rendering observers under NotifySVGChanged() since ancestor changes can't change a descendant from the point of view of the descendant's rendering observers anyway. (Since when rendering, rendering observers have the elements they reference resolve dimensions relative to them, etc., not their ancestor.)
Anyway, that bug forgot to remove DO_NOT_NOTIFY_RENDERING_OBSERVERS. It's no longer needed, so we should do that.
Created attachment 644941 [details] [diff] [review]