Prevent full wake lock from keeping device awake while dreaming.

A dream may itself hold a wake lock in order to keep the screen
bright as it runs.  However this wake lock also causes the device
to stay awake even when it is not plugged in which is undesirable.

This change makes full wake locks behave differently when napping
or dreaming.  The wake lock still keeps the screen bright but
it does not prevent the device from falling asleep.  This is
similar to our policy of ignoring full wake locks completely when
the device is manually put to sleep by the user.

Bug: 7295909
Change-Id: Id99e82d2143ae1a81629281d6407d7527efb8137

Author: Jeff Brown

services/java/com/android/server/power/PowerManagerService.java

@@ -127,6 +127,7 @@ public final class PowerManagerService extends IPowerManager.Stub
     private static final int WAKE_LOCK_SCREEN_DIM = 1 << 2;
     private static final int WAKE_LOCK_BUTTON_BRIGHT = 1 << 3;
     private static final int WAKE_LOCK_PROXIMITY_SCREEN_OFF = 1 << 4;
+    private static final int WAKE_LOCK_STAY_AWAKE = 1 << 5; // only set if already awake
 
     // Summarizes the user activity state.
     private static final int USER_ACTIVITY_SCREEN_BRIGHT = 1 << 0;
@@ -1172,16 +1173,25 @@ private void updateWakeLockSummaryLocked(int dirty) {
                         if (mWakefulness != WAKEFULNESS_ASLEEP) {
                             mWakeLockSummary |= WAKE_LOCK_CPU
                                     | WAKE_LOCK_SCREEN_BRIGHT | WAKE_LOCK_BUTTON_BRIGHT;
+                            if (mWakefulness == WAKEFULNESS_AWAKE) {
+                                mWakeLockSummary |= WAKE_LOCK_STAY_AWAKE;
+                            }
                         }
                         break;
                     case PowerManager.SCREEN_BRIGHT_WAKE_LOCK:
                         if (mWakefulness != WAKEFULNESS_ASLEEP) {
                             mWakeLockSummary |= WAKE_LOCK_CPU | WAKE_LOCK_SCREEN_BRIGHT;
+                            if (mWakefulness == WAKEFULNESS_AWAKE) {
+                                mWakeLockSummary |= WAKE_LOCK_STAY_AWAKE;
+                            }
                         }
                         break;
                     case PowerManager.SCREEN_DIM_WAKE_LOCK:
                         if (mWakefulness != WAKEFULNESS_ASLEEP) {
                             mWakeLockSummary |= WAKE_LOCK_CPU | WAKE_LOCK_SCREEN_DIM;
+                            if (mWakefulness == WAKEFULNESS_AWAKE) {
+                                mWakeLockSummary |= WAKE_LOCK_STAY_AWAKE;
+                            }
                         }
                         break;
                     case PowerManager.PROXIMITY_SCREEN_OFF_WAKE_LOCK:
@@ -1339,7 +1349,7 @@ private boolean isItBedTimeYetLocked() {
     private boolean isBeingKeptAwakeLocked() {
         return mStayOn
                 || mProximityPositive
-                || (mWakeLockSummary & (WAKE_LOCK_SCREEN_BRIGHT | WAKE_LOCK_SCREEN_DIM)) != 0
+                || (mWakeLockSummary & WAKE_LOCK_STAY_AWAKE) != 0
                 || (mUserActivitySummary & (USER_ACTIVITY_SCREEN_BRIGHT
                         | USER_ACTIVITY_SCREEN_DIM)) != 0;
     }