They're treated as plaintext, so we do check indentation and stuff, but do not apply code rules! Additionally, the style checker isn't quite smart enough to handle ObjC yet, so we have to adjust some of the rules a bit.
Most stuff already works because we frequently check style of ObjC headers.
Created attachment 229410 [details] patch This covers all of the obvious false positives in a few ObjC(++) files I tested, but I'm sure there will be more, which we can fix as they come up.
Created attachment 229411 [details] fix the test too
http://trac.webkit.org/changeset/167350