message: [tpu:profiler] Add infeed enqueue operation data to tf_op_stats.proto.
diff: @@ -61,6 +61,11 @@ message OpMetricsResult {
  message OpMetricsDbResult {
  // A bunch of OpMetricsResults.
  repeated OpMetricsResult metrics_db = 1;
  + // The total host infeed-enqueue duration in picoseconds.
  + optional uint64 total_host_infeed_enq_duration_ps = 2;
  + // 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;
  }
  // Result proto for StepInfo.
  