am 991475a2: Merge change I0e419fcf into eclair

Merge commit '991475a2e5dcb344299387521b52fb637d6b1e4d' into eclair-mr2

* commit '991475a2e5dcb344299387521b52fb637d6b1e4d':
  Add isScreenOn() to LocalPowerManager interface so we can call it from PhoneWindowManager