ENABLE_VIDEO_TRACK won't be defined, so the WebCore bits we need are missing. Patch coming.
Created attachment 181206 [details] Patch
Bug #105743 contains a patch that wraps the event target interface in build guards if a conditional is present on the IDL interface. This removes the compilation failures occurring when disabling video track. The build targets behind the ENABLE_VIDEO automake variable should also be moved into the general list and the DOM bindings should still compile without failures, though I haven't looked into that yet and I won't guarantee it's at all possible.
Fixed in bug #105743, landed as r138793. http://trac.webkit.org/changeset/138793
Comment on attachment 181206 [details] Patch Clearing review/cq flags.