IIUC, this is the last thing we should put it into IsoSubspace in WebCore side.
We should collect iterator classes in preprocess-idls.pl. And putting all of them into DOMIsoSubspaces class. And instead of using typedef-ed JSDOMIterator directly, we should create a class which is inheriting JSDOMIteratorImpl<Class>, and offering subspaceFor implementation. And another thing we should do is putting `void subspaceFor` implementation for JSDOMObject to ensure that any derived classes of JSDOMObject should not get allocated from non IsoSubspace.
Created attachment 392707 [details] Patch
Committed r258032: <https://trac.webkit.org/changeset/258032>
<rdar://problem/60172271>