I'm using Ubuntu 14.04. The original Firefox integrate with Unity perfectly. I want to use Palemoon, but unfortunately, it has no integration with unity/global menu. I tried to look at the default plugin/add-ons on Firefox, but the "Unity Integration" add-on description is just for web apps and not global menu. I even tried downloading vanilla Firefox from Mozilla site, but it doesn't integrate either with Unity, even with the same add-ons.
I saw this question, but it seems Palemoon nor vanilla Firefox doesn't have ui.use_unity_menubar
.
So I'm wondering where can I see the code for that. Is Canonical hardcode it into Firefox source? Is there a way to see it?