Revert 202639 "Use totmaps if available on chromeos"

Revert 202639 "Use totmaps if available on chromeos"

> Use totmaps if available on chromeos
> 
> We currently use statm on linux. This provides less than great results.
> We take total resident memory and subtract "shared pages" from it instead of
> using a count of pages that only this process has mapped.
> 
> On chromeos we've added totmaps which sums up the fields from the process'
> smaps.
> 
> BUG=125150
> TEST=Examine memory reports from about:memory and task manager, and compare
>      them to the sums of the results in the smaps.
> 
> R=thestig@chromium.org, willchan@chromium.org
> 
> Review URL: https://codereview.chromium.org/15779007

TBR=davemoore@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=202640

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=202878

[DaveMoore, 2013-05-28 20:25:00]

Committed patchset #1 manually as r202640.

[DaveMoore, 2013-05-29 15:42:08]

Committed patchset #2 manually as r202878.