Comment 51 for bug 219385

(In reply to comment #28)
> I expect we're not going to support gtk2 plug-ins inside gtk3 browser without
> OOP, right?

The only issue AFAIK would be a gtk2 java plugin.
Java plugins are "in-process by default on all platforms because of bugs
relating to window.java and various other things." (bug 640908 comment 5)

(I don't expect Xt plugins are using gtk2, but, I am trying to find time to review your patches to move Xt plugins OOP.)