The RefCounted inheritance need to be changed a little bit to avoid double inheritance and RefCountedCustomAllocated class need to be added to RefCounted.h, the reason is the same like in the case of NoncopyableCustomAllocated, bug #27228. (Some classes which customizes operator new are inherited from RefCounted, RefCounted is inherited from Noncopyable, but Noncopyable will be inherited from FastAllocBase. Conflicts need to be resolved.)
Created attachment 32671 [details] proposed patch
Landed in http://trac.webkit.org/changeset/45885.