Merge "Hold Display suspend blocker until doze starts" into qt-r1-dev

am: 48a86feefe

Change-Id: I15d47b96d0b937c720eca379d34a73da5f00a6d2

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

@@ -2735,6 +2735,17 @@ public final class PowerManagerService extends SystemService
         if (mScreenBrightnessBoostInProgress) {
             return true;
         }
+
+        // Because summoning the sandman is asyncronous, there is a time-gap where
+        // we release the display suspend blocker before the dream service acquires
+        // their own wakelock.  Within this gap, we can end up suspending before
+        // dream service has a chance to start.  To avoid this, we check if we want
+        // to doze and the sandman is scheduled and if so, keep the display on until
+        // that has passed.
+        if (mWakefulness == WAKEFULNESS_DOZING && mSandmanScheduled) {
+            return true;
+        }
+
         // Let the system suspend if the screen is off or dozing.
         return false;
     }