GUI -- Beginnings of structure for topology Overlay API.
- Re-implemented RequestSummary / ShowSummary in Alt implementation.

Change-Id: Idb86c7bf3ede8f8815abcb488bbf9b0a7041ef79
diff --git a/web/gui/src/main/java/org/onosproject/ui/impl/topo/TopoUiEvent.java b/web/gui/src/main/java/org/onosproject/ui/impl/topo/TopoUiEvent.java
index 32ff62b..957476c 100644
--- a/web/gui/src/main/java/org/onosproject/ui/impl/topo/TopoUiEvent.java
+++ b/web/gui/src/main/java/org/onosproject/ui/impl/topo/TopoUiEvent.java
@@ -29,6 +29,10 @@
      * Type of Topology UI Model events.
      */
     public enum Type {
+        // notification events
+        SUMMARY_UPDATE,
+
+        // unsolicited topology events
         INSTANCE_ADDED,
         INSTANCE_REMOVED,
         DEVICE_ADDED,