Revert of [Telemetry/Mac] Don't crash when setuid bit not set for powermetrics (patch...

Revert of [Telemetry/Mac] Don't crash when setuid bit not set for powermetrics (patchset #1 id:1 of https://codereview.chromium.org/654803002/)

Reason for revert:
Broke the Mac perf bots: http://crbug.com/423688

BUG=423688

Original issue's description:
> [Telemetry/Mac] Don't crash when setuid bit not set for powermetrics
>
> When Telemetry is run it will prompt to set the setuid bit for powermetrics, if the user opts not to do this, Telemetry will crash because the Python call to terminate() doesn't have appropriate privileges to kill the process.
>
> The fix is to send SIGTERM via `sudo kill`.
>
> BUG=None
>
> Committed: https://crrev.com/abb19226cb71da65d798ef3d18527331bc349605
> Cr-Commit-Position: refs/heads/master@{#299506}

TBR=dtu@chromium.org,jeremy@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=None

Review URL: https://codereview.chromium.org/656723004

Cr-Commit-Position: refs/heads/master@{#299667}