Guard against monkey crash

Bug: 27448755
Change-Id: I8345a274c979bf8ca1b4041c14318dd73810f79a
diff --git a/packages/SystemUI/src/com/android/systemui/qs/PagedTileLayout.java b/packages/SystemUI/src/com/android/systemui/qs/PagedTileLayout.java
index 2c5cb89..8ccf60d 100644
--- a/packages/SystemUI/src/com/android/systemui/qs/PagedTileLayout.java
+++ b/packages/SystemUI/src/com/android/systemui/qs/PagedTileLayout.java
@@ -77,7 +77,9 @@
 
     @Override
     public int getOffsetTop(TileRecord tile) {
-        return ((ViewGroup) tile.tileView.getParent()).getTop() + getTop();
+        final ViewGroup parent = (ViewGroup) tile.tileView.getParent();
+        if (parent == null) return 0;
+        return parent.getTop() + getTop();
     }
 
     @Override