29     bottom_arena_(nullptr),  in ArenaStack()
30     top_arena_(nullptr),  in ArenaStack()
31     top_ptr_(nullptr),  in ArenaStack()
32     top_end_(nullptr),  in ArenaStack()
44   bottom_arena_ = nullptr;  in Reset()
45   top_arena_  = nullptr;  in Reset()
46   top_ptr_ = nullptr;  in Reset()
47   top_end_ = nullptr;  in Reset()
59   if (UNLIKELY(top_arena_ == nullptr)) {  in AllocateFromNextArena()
61     top_arena_->next_ = nullptr;  in AllocateFromNextArena()
62   } else if (top_arena_->next_ != nullptr && top_arena_->next_->Size() >= allocation_size) {  in AllocateFromNextArena()
83   if (top_arena_ != nullptr) {  in UpdateBytesAllocated()
126   if (LIKELY(mark_arena_ != nullptr)) {  in Reset()
130   } else if (arena_stack_->bottom_arena_ != nullptr) {  in Reset()