message: Change the host-op result per TPU step from a single value to a collection of values.
diff: @@ -199,10 +199,22 @@ message HostOpsPerTpuStep {
  map<int32, int32> step_diffs = 5;
  }
  +message HostOpsDetailsPerCore {
  + // Map from core id to HostOpsPerTpuStep.
  + map<int32, HostOpsPerTpuStep> core_map = 1;
  +}
  +
  +message HostOpsDetailsPerHost {
  + // Map from hostname to a map from core id to HostOpsPerTpuStep.
  + map<string, HostOpsDetailsPerCore> host_map = 1;
  +}
  +
  // Result proto for the host ops for all TPU steps.
  message HostOpsResult {
  - // A sequence of HostOpsPerTpuStep (one for each TPU step)
  - repeated HostOpsPerTpuStep host_op_sequence = 1;
  + reserved 1; // (was repeated HostOpsPerTpuStep host_op_sequence)
  + // A sequence of records with one for each TPU step. Each record
  + // is a map from hostname to a map from core id to HostOpsPerTpuStep.
  + repeated HostOpsDetailsPerHost hostops_details = 2;
  }
  // Result proto for TfStatsHelper.
  