message: Remove a unnecessary DCHECK statement
diff: @@ -2142,7 +2142,6 @@ class LRUCache {
  if (lru_list_.empty()) return false;
  string key = lru_list_.back();
  auto it = cache_.find(key);
  - DCHECK(it != cache_.end());
  lru_list_.pop_back();
  delete it->second.op; // delete the object
  cache_.erase(it);
  