facebook/tornado — pull request #609 by sanyi (2012-10-10 12:46:16+00:00)
Title: HTTPConnection: different (differentiated) timeout errors for connect and communication

Duplicated _on_timeout with _on_connect_timeout.
_on_connect_timeout is triggered by connect timeout, this way we are
able to differentiate connection timeout from communication timeout.

Should work with anything the original version worked.