JSBool IsMarked() const {return 0 != (mMemberCount & XPC_NATIVE_IFACE_MARK_FLAG);}
JSBool IsMarked() const { return mCallingLangType & MARK_FLAG; }
    JSBool IsMarked() const                    {return 0 != (mMemberCount & XPC_NATIVE_IFACE_MARK_FLAG);}