I don't know about the history of VMHeap, but it has only one member function in it and Heap is the only client of that function. No member variable is defined. It does nothing special with its class. It is safe to merge the function into Heap.
Created attachment 390132 [details] PATCH
Comment on attachment 390132 [details] PATCH r=me, I think VMHeap is no longer necessary too.
Comment on attachment 390132 [details] PATCH Clearing flags on attachment: 390132 Committed r256088: <https://trac.webkit.org/changeset/256088>
All reviewed patches have been landed. Closing bug.
<rdar://problem/59285145>