Comment 2 for bug 1576639

I’ve changed the threshold to 100MB and tested on my M10.
This is too low, the system OOM killer kicks in before the browser gets a chance to unload background tabs:

May 2 16:25:39 ubuntu-phablet kernel: [ 3173.400686] (0)[54:kswapd0]lowmemorykiller: Killing 'webbrowser-app' (7341), adj 1, score_adj 110,
May 2 16:25:39 ubuntu-phablet kernel: [ 3173.400686] to free 550600kB on behalf of 'kswapd0' (54) because
May 2 16:25:39 ubuntu-phablet kernel: [ 3173.400686] cache 65196kB is below limit 65536kB for oom_score_adj 12
May 2 16:25:39 ubuntu-phablet kernel: [ 3173.400686] Free memory is 4344kB above reserved

Note that in my tests I had several apps open (both native and webapps, 4 of them in total) plus the browser with a dozen tabs including a live hangout, a google doc being edited, google maps, google plus, facebook and a 1080p movie trailer playing in youtube.

The last "free memory" value reported by the browser before it was killed was 237980KB, i.e. 232MB.
Note that this value is not just the free RAM, it’s the sum of the following entries from /proc/meminfo:
  MemFree
  Buffers
  Cached

(https://bazaar.launchpad.net/~phablet-team/webbrowser-app/trunk/view/head:/src/app/meminfo.cpp#L83)