unity8-dash + maliit-server crashes on arale (2016-04)

I'm seeing unity8-dash and maliit-server crashes lately on arale during power tests. They usually seem to happen together, and might be a recurrence of an earlier issue at the end of 2015.

I've collected a total of 19 unity8-dash crash dumps so far, and 14 for maliit-server, starting on 2016-04-04 and continuing to today. Prior to 2016-04, I saw similar paired crashes in January, December, and November, but those were mostly on krillin.

Here are some examples:

https://errors.ubuntu.com/oops/254319ac-1cd2-11e6-a5f5-fa163e30221b (unity8-dash)
https://errors.ubuntu.com/oops/1f7710b4-1cd2-11e6-998a-fa163e192766 (maliit)
http://people.canonical.com/~platform-qa/power-results/2016-05-18_02:04:57-arale-328-power_usage_video/3/

https://errors.ubuntu.com/oops/8f791fee-1cfd-11e6-9e43-fa163eec78fa (unity8-dash)
https://errors.ubuntu.com/oops/8a7c5786-1cfd-11e6-a175-fa163e8d4bab (maliit)
http://people.canonical.com/~platform-qa/power-results/2016-05-18_07:14:53-arale-329-power_usage_video/3/

https://errors.ubuntu.com/oops/9ef5c9f8-22ee-11e6-a2a7-fa163e839e11 (unity8-dash)
https://errors.ubuntu.com/oops/9d30a840-22ee-11e6-9c70-fa163e171d9b (maliit)
http://people.canonical.com/~platform-qa/power-results/2016-05-25_20:52:43-arale-333-power_usage_video/2/

https://errors.ubuntu.com/oops/fa1d1592-234e-11e6-85ab-fa163e8d4bab (unity8-dash)
https://errors.ubuntu.com/oops/f870ebc4-234e-11e6-9005-fa163eec78fa (maliit)
http://people.canonical.com/~platform-qa/power-results/2016-05-26_08:22:28-arale-336-power_usage_video/2/

The two usually coincide, but not always. Here is a diff between the test runs where each one occurred:
--- maliit.crashes
+++ unity8-dash.crashes
 2016-04-04_21:11:32-arale-28-power_usage_video/2/
+2016-04-09_20:49:41-arale-29-power_usage_display_on/12/
+2016-04-09_20:49:41-arale-29-power_usage_display_on/9/
+2016-04-10_04:19:02-arale-29-power_usage_video/6/
 2016-04-11_09:06:44-arale-30-power_usage_video/4/
 2016-04-20_22:56:38-arale-308-power_usage_video/5/
-2016-04-25_17:11:09-arale-31-power_usage_display_on/8/
+2016-04-26_01:41:35-arale-31-power_usage_video/4/
 2016-05-04_22:58:30-arale-315-power_usage_music/2/
 2016-05-05_05:05:20-arale-316-power_usage_video/2/
+2016-05-06_22:49:51-arale-32-power_usage_display_on/12/
+2016-05-12_21:58:22-arale-319-power_usage_bt_on_wifi_disconnected/1/
 2016-05-13_08:09:00-arale-321-power_usage_video/7/
 2016-05-13_14:50:11-arale-321-power_usage_bt_on_wifi_disconnected/1/
 2016-05-14_01:49:40-arale-324-power_usage_idle/1/

I'm assuming these have a common cause, even if it doesn't always kill both processes.

It may also be related to bug 1586276 and bug 1586255, which started happening at the same time.