Refactored LLDP link discovery to be shared by multiple providers

Change-Id: Ia2253ff6bb39186e936ddbaff0c416aa5be6e117
diff --git a/providers/lldp/src/main/java/org/onosproject/provider/lldp/impl/LldpLinkProvider.java b/providers/lldp/src/main/java/org/onosproject/provider/lldp/impl/LldpLinkProvider.java
index 3a6b7e3..23f67d1 100644
--- a/providers/lldp/src/main/java/org/onosproject/provider/lldp/impl/LldpLinkProvider.java
+++ b/providers/lldp/src/main/java/org/onosproject/provider/lldp/impl/LldpLinkProvider.java
@@ -62,6 +62,8 @@
 import org.onosproject.net.packet.PacketService;
 import org.onosproject.net.provider.AbstractProvider;
 import org.onosproject.net.provider.ProviderId;
+import org.onosproject.provider.lldpcommon.LinkDiscoveryContext;
+import org.onosproject.provider.lldpcommon.LinkDiscovery;
 import org.onosproject.store.service.ConsistentMapException;
 import org.osgi.service.component.ComponentContext;
 import org.slf4j.Logger;
@@ -169,7 +171,7 @@
             label = "Number of millis beyond which links will be considered stale")
     private int staleLinkAge = DEFAULT_STALE_LINK_AGE;
 
-    private final DiscoveryContext context = new InternalDiscoveryContext();
+    private final LinkDiscoveryContext context = new InternalDiscoveryContext();
     private final InternalRoleListener roleListener = new InternalRoleListener();
     private final InternalDeviceListener deviceListener = new InternalDeviceListener();
     private final InternalPacketProcessor packetProcessor = new InternalPacketProcessor();
@@ -718,7 +720,7 @@
     /**
      * Provides processing context for the device link discovery helpers.
      */
-    private class InternalDiscoveryContext implements DiscoveryContext {
+    private class InternalDiscoveryContext implements LinkDiscoveryContext {
         @Override
         public MastershipService mastershipService() {
             return masterService;