15     char*   fBegin; // start of used section in this chunk  member
24         fBegin  = fEnd = NULL;  in init()
81     if (NULL == first->fBegin) {  in push_front()
86         begin = first->fBegin - fElemSize;  in push_front()
97     first->fBegin = begin;  in push_front()
121     if (NULL == last->fBegin) {  in push_back()
123         last->fBegin = last->start();  in push_back()
124         end = last->fBegin + fElemSize;  in push_back()
159     if (first->fBegin == NULL) {  // we were marked empty from before  in pop_front()
167     char* begin = first->fBegin + fElemSize;  in pop_front()
171         first->fBegin = begin;  in pop_front()
172         SkASSERT(first->fBegin);  in pop_front()
173         fFront = first->fBegin;  in pop_front()
175         first->fBegin = first->fEnd = NULL;  // mark as empty  in pop_front()
179             SkASSERT(first->fNext->fBegin);  in pop_front()
180             fFront = first->fNext->fBegin;  in pop_front()
202     SkASSERT(end >= last->fBegin);  in pop_back()
204     if (end > last->fBegin) {  in pop_back()
209         last->fBegin = last->fEnd = NULL;    // mark as empty  in pop_back()
258             } while (fCurBlock != NULL && fCurBlock->fBegin == NULL);  in next()
259             next = fCurBlock ? fCurBlock->fBegin : NULL;  in next()
273         SkASSERT(prev >= fCurBlock->fBegin - fElemSize);  in prev()
274         if (prev < fCurBlock->fBegin) { // exhausted this chunk, move to prior  in prev()
296         while (fCurBlock && NULL == fCurBlock->fBegin) {  in reset()
299         fPos = fCurBlock ? fCurBlock->fBegin : NULL;  in reset()