People holding partial wake locks now get blamed for CPU usage.

For the duration of the wake lock, 50% of all CPU usage is now
accounted against the app(s) holding partial wake locks, evenly
distributed between them.  This is only while the device is on
battery and screen off.

Change-Id: I3e5c978b792b6ef17bf8540705bfe8343dadd464
4 files changed