Fixing up some folder-related drag and drop bugs

Change-Id: I712ffd0ccfc0154a5a9e74e3f585157a86986882
diff --git a/src/com/android/launcher2/FolderInfo.java b/src/com/android/launcher2/FolderInfo.java
index 12ed27c..805a51f 100644
--- a/src/com/android/launcher2/FolderInfo.java
+++ b/src/com/android/launcher2/FolderInfo.java
@@ -86,8 +86,15 @@
         }
     }
 
+    void itemsChanged() {
+        for (int i = 0; i < listeners.size(); i++) {
+            listeners.get(i).onItemsChanged();
+        }
+    }
+
     interface FolderListener {
         public void onAdd(ShortcutInfo item);
         public void onRemove(ShortcutInfo item);
+        public void onItemsChanged();
     }
 }