message: Refine comment of share_session_state_in_clusterspec_propagation.
diff: @@ -445,8 +445,23 @@ message ConfigProto {
  // experimental.
  bool collective_nccl = 7;
  - // If true, any resources such as Variables used in the session will be
  - // shared with other sessions even if ClusterSpec Propagation is enabled.
  + // In the following words, session state means the value of a variable,
  + // elements in a hash table, or any other resource, accessible by worker
  + // sessions held by a TF server.
  + //
  + // When clusterspec propagation is used, the value of isolate_session_state
  + // is ignored when deciding whether to share session states in a TF server.
  + // - If share_session_state_in_clusterspec_propagation is true, session
  + // states are shared.
  + // - If share_session_state_in_clusterspec_propagation is false, session
  + // states are isolated.
  + //
  + // When clusterspec propagation is not used, the value of
  + // share_session_state_in_clusterspec_propagation is ignored when deciding
  + // whether to share session states in a TF server.
  + // - If isolate_session_state is true, session states are isolated.
  + // - If isolate_session_state is false, session states are shared.
  + //
  // TODO(mrry): This field is a patch for isolate_session_state and an
  // uniform API with flexibility in distributed runtime is needed.
  bool share_session_state_in_clusterspec_propagation = 8;
  