Revert 221966 "Revert 221944 "Add UMA to report Preferences File..."

Revert 221966 "Revert 221944 "Add UMA to report Preferences File..."

Re-apply and disable for Chrome Frame.

> Revert 221944 "Add UMA to report Preferences File Corruption"
> 
> Breaks chrome_frame_tests on Win Aura.
> http://test-results.appspot.com/dashboards/flakiness_dashboard.html#group=%40ToT%20Chromium&testType=chrome_frame_tests&builder=Win%20Aura%20Tests%20(1)
> 
> > Add UMA to report Preferences File Corruption
> > Adds PrefMetricsService methods to track changes to user preferences
> > that happen outside of Chrome and report discrepancies via UMA.
> > 
> > BUG=266569
> > 
> > Review URL: https://chromiumcodereview.appspot.com/22676002
> 
> TBR=bbudge@chromium.org
> 
> Review URL: https://codereview.chromium.org/23597020

TBR=bbudge@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=221972

[Vitaly Buka (NO REVIEWS), 2013-09-09 04:06:30]

Committed patchset #1 manually as r221972.

[Vitaly Buka (NO REVIEWS), 2013-09-09 04:12:11]

https://codereview.chromium.org/23788010/diff/1/trunk/src/chrome/browser/pref...
File trunk/src/chrome/browser/prefs/pref_metrics_service.cc (right):

https://codereview.chromium.org/23788010/diff/1/trunk/src/chrome/browser/pref...
trunk/src/chrome/browser/prefs/pref_metrics_service.cc:319: // TODO(bbudge) Fix
failing browser_tests and so we can remove this test.
Uhh, I have messed up comment here.
I am not going to fix this to simplify rollback if it would be necessary.