Fix a BadTokenException in DreamOverlayService.

This exception occurs when adding the DreamOverlayService's DecorView to
WindowManager (presumably because the service has already been
destroyed).

Test: atest DreamOverlayServiceTest
Bug: 221872102
Change-Id: I9eb40c518dc24a92ea06949a0701295883c4f150

packages/SystemUI/src/com/android/systemui/dreams/DreamOverlayService.java

@@ -65,6 +65,9 @@ public class DreamOverlayService extends android.service.dreams.DreamOverlayServ
     // A reference to the {@link Window} used to hold the dream overlay.
     private Window mWindow;
 
+    // True if the service has been destroyed.
+    private boolean mDestroyed;
+
     private final Complication.Host mHost = new Complication.Host() {
         @Override
         public void requestExitDream() {
@@ -134,6 +137,7 @@ public class DreamOverlayService extends android.service.dreams.DreamOverlayServ
         mPreviewComplication.setDreamLabel(null);
         mStateController.removeComplication(mPreviewComplication);
         mStateController.setPreviewMode(false);
+        mDestroyed = true;
         super.onDestroy();
     }
 
@@ -141,6 +145,11 @@ public class DreamOverlayService extends android.service.dreams.DreamOverlayServ
     public void onStartDream(@NonNull WindowManager.LayoutParams layoutParams) {
         setCurrentState(Lifecycle.State.STARTED);
         mExecutor.execute(() -> {
+            if (mDestroyed) {
+                // The task could still be executed after the service has been destroyed. Bail if
+                // that is the case.
+                return;
+            }
             mStateController.setShouldShowComplications(shouldShowComplications());
             mStateController.setPreviewMode(isPreviewMode());
             if (isPreviewMode()) {

packages/SystemUI/tests/src/com/android/systemui/dreams/DreamOverlayServiceTest.java

@@ -19,6 +19,7 @@ package com.android.systemui.dreams;
 import static com.google.common.truth.Truth.assertThat;
 
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
@@ -222,4 +223,25 @@ public class DreamOverlayServiceTest extends SysuiTestCase {
         verify(mLifecycleRegistry).setCurrentState(Lifecycle.State.DESTROYED);
         verify(mStateController).setOverlayActive(false);
     }
+
+    @Test
+    public void testDecorViewNotAddedToWindowAfterDestroy() throws Exception {
+        when(mDreamOverlayContainerView.getParent())
+                .thenReturn(mDreamOverlayContainerViewParent)
+                .thenReturn(null);
+
+        final IBinder proxy = mService.onBind(new Intent());
+        final IDreamOverlay overlay = IDreamOverlay.Stub.asInterface(proxy);
+
+        // Inform the overlay service of dream starting.
+        overlay.startDream(mWindowParams, mDreamOverlayCallback);
+
+        // Destroy the service.
+        mService.onDestroy();
+
+        // Run executor tasks.
+        mMainExecutor.runAllReady();
+
+        verify(mWindowManager, never()).addView(any(), any());
+    }
 }