TopologyManager should not process switch removed and port down messages...

TopologyManager should not process switch removed and port down messages explicitly as they are processed by link discovery module and generate corresponding link removed events.

src/main/java/net/floodlightcontroller/topology/TopologyManager.java

@@ -837,12 +837,18 @@ public class TopologyManager implements
         return Command.STOP;
     }
 
+
+    /**
+     * Updates concerning switch disconnect and port down are not processed.
+     * LinkDiscoveryManager is expected to process those messages and send
+     * multiple link removed messages.  However, all the updates from
+     * LinkDiscoveryManager would be propagated to the listeners of topology.
+     */
     @LogMessageDoc(level="ERROR",
             message="Error reading link discovery update.",
             explanation="Unable to process link discovery update",
             recommendation=LogMessageDoc.REPORT_CONTROLLER_BUG)
     public void applyUpdates() {
-
         appliedUpdates.clear();
         LDUpdate update = null;
         while (ldUpdates.peek() != null) {
@@ -861,12 +867,7 @@ public class TopologyManager implements
             } else if (update.getOperation() == UpdateOperation.LINK_REMOVED){
                 removeLink(update.getSrc(), update.getSrcPort(), 
                            update.getDst(), update.getDstPort());
-            } else if (update.getOperation() == UpdateOperation.SWITCH_REMOVED) {
-                removeSwitch(update.getSrc());
-            } else if (update.getOperation() == UpdateOperation.PORT_DOWN) {
-                removeSwitchPort(update.getSrc(), update.getSrcPort());
             }
-
             // Add to the list of applied updates.
             appliedUpdates.add(update);
         }