Adding ability to wipe-out UI model cache and network config.

Change-Id: I3d4aecb989c1d4fc2589471fa3ddd53f62c49eb5
diff --git a/web/gui/src/main/java/org/onosproject/ui/impl/UiExtensionManager.java b/web/gui/src/main/java/org/onosproject/ui/impl/UiExtensionManager.java
index a50fd1b..e384677 100644
--- a/web/gui/src/main/java/org/onosproject/ui/impl/UiExtensionManager.java
+++ b/web/gui/src/main/java/org/onosproject/ui/impl/UiExtensionManager.java
@@ -61,6 +61,7 @@
 import org.onosproject.ui.impl.topo.Topo2TrafficMessageHandler;
 import org.onosproject.ui.impl.topo.Topo2ViewMessageHandler;
 import org.onosproject.ui.impl.topo.Traffic2Overlay;
+import org.onosproject.ui.impl.topo.model.UiSharedTopologyModel;
 import org.onosproject.ui.lion.LionBundle;
 import org.onosproject.ui.lion.LionUtils;
 import org.slf4j.Logger;
@@ -144,6 +145,9 @@
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected StorageService storageService;
 
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    private UiSharedTopologyModel sharedModel;
+
     // User preferences
     private ConsistentMap<String, ObjectNode> prefsConsistentMap;
     private Map<String, ObjectNode> prefs;
@@ -344,6 +348,11 @@
     }
 
     @Override
+    public void refreshModel() {
+        sharedModel.reload();
+    }
+
+    @Override
     public Set<String> getUserNames() {
         ImmutableSet.Builder<String> builder = ImmutableSet.builder();
         prefs.keySet().forEach(k -> builder.add(userName(k)));