Merge "Floss: use QuitWhenIdle for thread-safety"

    CHECK_NE(thread_id_, base::PlatformThread::CurrentId())

        << __func__ << " should not be called on the thread itself. "

        << "Otherwise, deadlock may happen.";

    if (!message_loop_->task_runner()->PostTask(

            FROM_HERE, run_loop_->QuitWhenIdleClosure())) {

      LOG(FATAL) << __func__

                 << ": failed to post task to message loop for thread "

                 << *this;

    }

    run_loop_->QuitWhenIdle();

  }

  thread_->join();

  {