Remove NPE inside WidgetsListAdapter during monkey actor test
b/22518383

Change-Id: I1a683c49be93af150f7873390b723cee0d4ac5df
diff --git a/src/com/android/launcher3/widget/WidgetsListAdapter.java b/src/com/android/launcher3/widget/WidgetsListAdapter.java
index d2ea252..a54626a 100644
--- a/src/com/android/launcher3/widget/WidgetsListAdapter.java
+++ b/src/com/android/launcher3/widget/WidgetsListAdapter.java
@@ -87,6 +87,9 @@
 
     @Override
     public int getItemCount() {
+        if (mWidgetsModel == null) {
+            return 0;
+        }
         return mWidgetsModel.getPackageSize();
     }