We send email from cbuildbot based the build config values "health_alert_recipients" and "health_threshold".

The logic is to email recipients if a given build config fails more than threshhold times in a row.

Cons:

A) This mechanism does not work if cbuildbot does not run to completion normally (crash, scheduling issue, early crash, violent abort, etc).

B) There is a mechanism involving GS used to track the "fail streaks" which is otherwise unused, and there are no users with threshold > 1.


I propose that we remove "health_threshold" and the cbuildbot mechansim for sending email. In addition, we can then remove our gmail credentials from build machines.

Instead, we update our buildbucket requests to populate LUCI Notify fields for build configs that set "health_alert_recipients" to send email on failure (this may require a tweak to LUCI Notify, but an easy one).

Pros:

A) Notifications become more robust and consistent with tryjob emails.
B) We get to delete "pass/fail streak" code.
C) We get to delete Email generation code.
D) We get to remove Gmail credentials.