Fixing the Chromoting Test Driver host online retry logic

Fixing the Chromoting Test Driver host online retry logic

In order to increase the reliability of the CTD, logic was added to
refetch the host list every few seconds for ~1 minute until we saw an
online host with a matching name and jid.  This was to combat a backend
propagation delay we had occasionally seen.

We are still seeing failures for this code on the waterfall though as
the logic is not actually executed if the first check fails.  This logic
needs to be fixed so the tool is more tolerant to potential propagation
delays.

The code that checks for the host being available did not have any unit
tests so I added those as well.

BUG=600763
Committed: https://crrev.com/afb0295ebb94bbaf0b118c9fd364ca7434b27c78
Cr-Commit-Position: refs/heads/master@{#385319}

[joedow, 2016-04-05 22:37:10]

joedow@chromium.org changed reviewers:
+ jamiewalch@chromium.org, mmeade@chromium.org

[joedow, 2016-04-05 22:37:10]

This change addresses a problem that is causing failures on our waterfall.

The Chromoting Test Driver (CTD) has logic to refresh its internal host list if
the host with a matching name/jid is not found.  This is meant to work around
the propagation delays we sometimes see.  I debugged a failure this morning and
found that this retry logic was not being invoked which was causing unnecessary
failures.

I fixed the logic error, added unit tests, and cleaned up some duplicated code
used to check if the host existed and was online.

mmeade for test owner review, jamie for committer LGTM.

PTAL!
Joe

[Mike Meade, 2016-04-05 22:43:06]

lgtm

[Jamie, 2016-04-05 22:46:43]

LGTM; thanks for the quick turn-around!

[joedow, 2016-04-05 22:50:15]

The CQ bit was checked by joedow@chromium.org

[commit-bot: I haz the power, 2016-04-05 22:50:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1864433005/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1864433005/20001

[commit-bot: I haz the power, 2016-04-05 23:13:40]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-04-05 23:15:48]

Description was changed from

==========
Fixing the Chromoting Test Driver host online retry logic

In order to increase the reliability of the CTD, logic was added to
refetch the host list every few seconds for ~1 minute until we saw an
online host with a matching name and jid.  This was to combat a backend
propagation delay we had occasionally seen.

We are still seeing failures for this code on the waterfall though as
the logic is not actually executed if the first check fails.  This logic
needs to be fixed so the tool is more tolerant to potential propagation
delays.

The code that checks for the host being available did not have any unit
tests so I added those as well.

BUG=600763
==========

to

==========
Fixing the Chromoting Test Driver host online retry logic

In order to increase the reliability of the CTD, logic was added to
refetch the host list every few seconds for ~1 minute until we saw an
online host with a matching name and jid.  This was to combat a backend
propagation delay we had occasionally seen.

We are still seeing failures for this code on the waterfall though as
the logic is not actually executed if the first check fails.  This logic
needs to be fixed so the tool is more tolerant to potential propagation
delays.

The code that checks for the host being available did not have any unit
tests so I added those as well.

BUG=600763

Committed: https://crrev.com/afb0295ebb94bbaf0b118c9fd364ca7434b27c78
Cr-Commit-Position: refs/heads/master@{#385319}
==========

[commit-bot: I haz the power, 2016-04-05 23:15:49]

Patchset 2 (id:??) landed as
https://crrev.com/afb0295ebb94bbaf0b118c9fd364ca7434b27c78
Cr-Commit-Position: refs/heads/master@{#385319}