||The callback will be called when a lock topic changes its lock
Possible states are:
- "unlocked" - nobody holds the wake lock.
- "locked-foreground" - at least one window holds the wake lock,
and it is visible.
- "locked-background" - at least one window holds the wake lock,
but all of them are hidden.
@param aTopic The resource name related to the wake lock.
@param aState The wake lock state
||For use with non-content code.
||Acquire a wake lock on behalf of a given process (aContentParent).
This method stands in contrast to nsIPowerManagerService::NewWakeLock,
which acquires a wake lock on behalf of the /current/ process.
NewWakeLockOnBehalfOfProcess is different from NewWakeLock in that
- The wake lock unlocks itself if the /given/ process dies, and
- The /given/ process shows up in WakeLockInfo::lockingProcesses.
||Null windows are allowed. A wake lock without associated window
is always considered invisible.