Class CompareByTime

tensorflow/python/grappler/cost_analyzer.cc:133–137

    ops_.push_back(op.second);
  }
  struct CompareByTime {
    bool operator()(const OpPerfSummary& a, const OpPerfSummary& b) const {
      return a.time > b.time;
    }
  };
  std::stable_sort(ops_.begin(), ops_.end(), CompareByTime());
}