Please make the gconf dependency depend on USE=gnome or something similar: I copied xulrunner and firefox in my overlay, just removing the gconf dependency (I have not installed gconf and do not intend to install gnome) and it compiles and runs fine, so this dependency seems not really necessary for a non-gnome user. According to the ChangeLog comments, it appears that I will not be able to set the default browser in gnome, but since I am not a gnome user, this option would be useless anyway: It seems rather pointless to install serious gnome dependencies just to be able to set a gnome option which I will never use. I guess most non-Gnome users will appreciate if you add a corresponding USE-flag to make the gconf dependency optional.
It is not as simple. If someone as gconf installed, xulrunner will auto-magically depend on it. The current configure script does not permit to disable that behavior ATM. *** This bug has been marked as a duplicate of bug 360307 ***