message: Add the total device time and total host time to tf_op_stats.
diff: @@ -66,6 +66,10 @@ message OpMetricsDbResult {
  // The total of the difference between the start times of two
  // consecutive infeed-enqueues (per host) in picoseconds.
  optional uint64 total_host_infeed_enq_start_timestamp_ps_diff = 3;
  + // The total device time in microseconds.
  + optional double total_device_time_in_us = 4;
  + // The total host time in microseconds.
  + optional double total_host_time_in_us = 5;
  }
  // Result proto for StepInfo.
  