If ssl_do_write takes more than one iteration, ssl3_output_cert_chain would be called an extra time. This is very unlikely in practice because of the buffer BIO. Change-Id: Ic1ae9752a8837bb404429fc60306c659208c6185 Reviewed-on: https://boringssl-review.googlesource.com/5340 Reviewed-by: Adam Langley <agl@google.com>kris/onging/CECPQ3_patch15