message: Make MemoryUsageTracker::EndInstruction() return error status instead of crashing due to CHECK fails. This crashes the layout autotuner.
diff: @@ -745,7 +745,7 @@ Status MemoryUsageTracker::EndInstruction() {
  for (BufferId buffer_id : in_progress_item_->buffers_used) {
  Buffer& buffer = buffers_.at(buffer_id);
  buffer.unfinished_user_count--;
  - CHECK_GE(buffer.unfinished_user_count, 0)
  + TF_RET_CHECK(buffer.unfinished_user_count >= 0)
  << buffer.ToString() << " has negative unfinished user count.";
  if (buffer.unfinished_user_count == 0) {
  // Buffer is now dead.
  