Revert of Revert "Remove CpuMonitor and related, unused, code."

Revert of Revert "Remove CpuMonitor and related, unused, code." (patchset #1 id:1 of https://codereview.webrtc.org/1287913004/ )

Reason for revert:
Re-landing the change that removes the CpuMonitor class after having fixed the build issue in Chromium.

Original issue's description:
> Revert "Remove CpuMonitor and related, unused, code."
> 
> This reverts commit 1a24012680f25440aa1d117373df2af14cdc2fc1.
> 
> TBR=tommi@webrtc.org,pthatcher@webrtc.org
> BUG=
> 
> This breaks 
> http://build.chromium.org/p/chromium.webrtc.fyi/builders/Linux/builds/20148/steps/compile/logs/stdio
> 
> Committed: https://chromium.googlesource.com/external/webrtc/+/a472e968c95fb14e63ec42f453551d0967573ea8

TBR=pthatcher@webrtc.org,tommi@webrtc.org,guoweis@webrtc.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

[tommi (sloooow) - chröme, 2015-08-19 10:58:03]

Created Revert of Revert "Remove CpuMonitor and related, unused, code."

[commit-bot: I haz the power, 2015-08-19 10:58:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1296763007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1296763007/1

[commit-bot: I haz the power, 2015-08-19 10:58:12]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-19 10:58:12]

No L-G-T-M from a valid reviewer yet. Only full committers are accepted.
Even if an L-G-T-M may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[tommi (sloooow) - chröme, 2015-08-19 11:00:09]

doh, signed in with the wrong account... closing.