See https://areweslimyet.com/mobile/ circa 25 feb - the pushlog range for the regression is http://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=179a23a14368&tochange=cdc3588c8ce2
See bug 700023 comment 10 for explanation. I've posted a patch there to revert the pref on Android for now, and filed bug 847344 about improving our use of the API so as to reduce the RAM impact.
Thanks! I'll mark this as fixed, since the regression has been undone.
Just to follow up, the AWSY mobile graph is now catching up on the backlog, and the pref-flip does appear to have fixed the regression. Thanks!