42         : fHead(std::move(op)), fTail(fHead.get()) {  in List()
50     fHead = std::move(that.fHead);  in operator =()
58     SkASSERT(fHead);  in popHead()
59     auto temp = fHead->cutChain();  in popHead()
60     std::swap(temp, fHead);  in popHead()
61     if (!fHead) {  in popHead()
72     SkASSERT(head == fHead.get());  in removeOp()
76         SkASSERT(op == fHead.get());  in removeOp()
94     if (fHead) {  in pushHead()
95         op->chainConcat(std::move(fHead));  in pushHead()
96         fHead = std::move(op);  in pushHead()
98         fHead = std::move(op);  in pushHead()
99         fTail = fHead.get();  in pushHead()
111     if (fHead) {  in validate()
113         fHead->validateChain(fTail);  in validate()