Bug 1619851 fixed a regression in PWMGR_PROMPT_*_ACTION telemetry so it only records when a capture doorhanger is shown but it still has the problem of not recording when the only the key icon is shown and it records the first time a doorhanger is shown but simply updating the contents of the doorhanger (e.g. tracking edits to username/password fields) counts as a new doorhanger.

For bug 1560468 we should have a way of updating the doorhanger contents without creating a new popup notification instance and then this bug can use event telemetry to record the whole funnel:

• key icon shown
• doorhanger opened (updating the contents of the doorhanger for the same document shouldn't record this twice)
• action taken in the doorhanger