Merge "Defer stop for all activities becoming invisible" into pi-dev

services/core/java/com/android/server/am/ActivityStack.java

@@ -1654,6 +1654,16 @@ class ActivityStack<T extends StackWindowController> extends ConfigurationContai
     void addToStopping(ActivityRecord r, boolean scheduleIdle, boolean idleDelayed) {
         if (!mStackSupervisor.mStoppingActivities.contains(r)) {
             mStackSupervisor.mStoppingActivities.add(r);
+
+            // Some activity is waiting for another activity to become visible before it's being
+            // stopped, which means that we also want to wait with stopping this one to avoid
+            // flickers.
+            if (!mStackSupervisor.mActivitiesWaitingForVisibleActivity.isEmpty()
+                    && !mStackSupervisor.mActivitiesWaitingForVisibleActivity.contains(r)) {
+                if (DEBUG_SWITCH) Slog.i(TAG_SWITCH, "adding to waiting visible activity=" + r
+                        + " existing=" + mStackSupervisor.mActivitiesWaitingForVisibleActivity);
+                mStackSupervisor.mActivitiesWaitingForVisibleActivity.add(r);
+            }
         }
 
         // If we already have a few activities waiting to stop, then give up

services/core/java/com/android/server/am/ActivityStackSupervisor.java

@@ -3937,6 +3937,10 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
                         stops = new ArrayList<>();
                     }
                     stops.add(s);
+
+                    // Make sure to remove it in all cases in case we entered this block with
+                    // shouldSleepOrShutDown
+                    mActivitiesWaitingForVisibleActivity.remove(s);
                     mStoppingActivities.remove(activityNdx);
                 }
             }