The power wash loop does not sound like single process mash relevant. 

Base on my old knowledge of the webui based flow, when user clicks "Continue" button on reset screen, code runs to ResetScreen::OnUserAction [1], which should eventually ask session_manager daemon to start wipe. Do we see "Starting Powerwash" in /var/log/chrome/chrome ? If we see that, it means the StartDeviceWipe call has happened. Then we should look at /var/log/messages to see whether session_manager dump anything there to indicate why the wipe is not started.

[1] https://cs.chromium.org/chromium/src/chrome/browser/chromeos/login/screens/reset_screen.cc?rcl=9bd27cf64264b645d6793b3380be18921c87e217&l=219

+rkc, who could help debugging power wash these days? Are we still using the webui based one ?

Fletcher, can you confirm this is different from  issue 921161 ?

This seems separate from 921161, since in this case powerwash is not even starting. I ran through the flow from #1 without enabling the SingleProcessMash flag and it rebooted, powerwashed, and got to OOBE without issue so I think this is probably related to that particular flag.

It looks like this is SingleProcessMash specific.

+lprazdnik, can you be more specific about which powerwash dialog you are talking about? The one inside the session (after login) from settings where you start the powerwash process? Or the one that appears immediately after reboot? (The former has title "Restart your device" and the latter has title "Reset this Chrome device".)

Fletcher, assuming powerwash can be started, would  issue 921161  cause a powerwash loop?

I cannot reproduce the powerwash loop in 73.0.3669.0 (11574.0.0) on eve, either with or without SingleProcessMash enabled.

I cannot reproduce problems starting powerwash, either with or without SingleProcessMash enabled.

I tried:
* Enable SingleProcessMash in about:flags and restart
* Ensure ChromeVox is enabled both at login screen and in device owner session.
* Login as owner.
* Open settings, advanced with mouse
* Click "powerwash" with mouse
* Navigate around powerwash dialog with Search-arrows and tab. This worked OK. Focus did not move to the shelf.
* Open system tray with Alt-Shift-S. Focus moves to shelf and I can tab around.
* Close system tray. Focus moves back to powerwash dialog.
* Press Powerwash button by pressing return.
* Device reboots and shows the on-startup powerwash dialog.
* I can navigate this powerwash dialog with ChromeVox search-arrow keys and tab.
* Pressing the powerwash button with enter resulted in the device being powerwashed.

I can repro a bug where ChromeVox won't move focus from the shelf to the "Reset this Chrome device" dialog. This happens with and without SingleProcessMash. I'll file a separate bug for that.

Filed issue 923582 for ChromeVox highlight being stuck in the shelf.

Re #5

> Fletcher, assuming powerwash can be started, would   issue 921161   cause a powerwash loop?

Yes, when switching from verified mode to dev mode on a chromebook, there was a bug where the marker file was not being created so the device kept rebooting and powerwashing. That should be fixed now however.

I think the root cause here was  issue 921161 . Issue 923582 covers ChromeVox highlight.

@Jamescook, as far as I know it was the dialog that that had the restart your device button. However, after trying to repro this the next day, the powerwash worked successfully. I'm not sure if it was just my device that day but perhaps it is something to look into.