flowrule states functional

Change-Id: Id310f146d4ef2a59993f31d60062464a24df4560
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleEvent.java b/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleEvent.java
index ce8e700..b17449d 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleEvent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleEvent.java
@@ -19,7 +19,12 @@
         /**
          * Signifies that a flow rule has been removed.
          */
-        RULE_REMOVED
+        RULE_REMOVED,
+
+        /**
+         * Signifies that a rule has been updated.
+         */
+        RULE_UPDATED
     }
 
     /**