Modified the PerformanceMonitor to not use test/ code for enumerating Chrome processes.
Separated out basic performance metrics gathering in the PerformanceMonitor to run independently from the metrics/events database code. The former will now run even without the performance-monitor-gathering flag.
Added an UMA event which triggers when the browser process never runs below X CPU utilization over a period of Y seconds.
BUG=279660, 273320
Review URL: https://codereview.chromium.org/
23825004
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226466 0039d316-1c4b-4281-b951-d872f2087c98