This was created for B2G and isn't really useful otherwise. It only works on
Linux, and it's behind the memory.system_memory_reporter pref, which is false
by default.
The patch also removes LinuxUtils.{h,cpp}, which is no longer used.
--HG--
extra : rebase_source : b97a018be11a79f83855a73b88020bfa86e60f78