am fa68ab4f: PowerManagerService: Add missing synchronization in mAutoBrightnessTask.

Merge commit 'fa68ab4fb0750b429c43af1d0c20539462ba6746' into eclair-mr2

* commit 'fa68ab4fb0750b429c43af1d0c20539462ba6746':
  PowerManagerService: Add missing synchronization in mAutoBrightnessTask.