Refining driver subsystem to facilitate coordinated start-up.

- for ONOS-6402

Change-Id: I7f64fc62ad1d451fcf55624b2422b60631a3c8e8
diff --git a/core/net/src/test/java/org/onosproject/net/packet/impl/PacketManagerTest.java b/core/net/src/test/java/org/onosproject/net/packet/impl/PacketManagerTest.java
index 5e0a432..095d797 100644
--- a/core/net/src/test/java/org/onosproject/net/packet/impl/PacketManagerTest.java
+++ b/core/net/src/test/java/org/onosproject/net/packet/impl/PacketManagerTest.java
@@ -33,7 +33,9 @@
 import org.onosproject.net.device.DeviceServiceAdapter;
 import org.onosproject.net.driver.AbstractHandlerBehaviour;
 import org.onosproject.net.driver.DefaultDriver;
+import org.onosproject.net.driver.DriverRegistry;
 import org.onosproject.net.driver.impl.DriverManager;
+import org.onosproject.net.driver.impl.DriverRegistryManager;
 import org.onosproject.net.flow.DefaultTrafficTreatment;
 import org.onosproject.net.packet.DefaultOutboundPacket;
 import org.onosproject.net.packet.OutboundPacket;
@@ -84,11 +86,13 @@
         mgr.coreService = new TestCoreService();
         providerRegistry = mgr;
         mgr.activate();
-        driverService = new TestDriverManager();
-        driverService.addDriver(new DefaultDriver("foo", ImmutableList.of(), "", "", "",
-                                                  ImmutableMap.of(PacketProgrammable.class,
-                                                                  TestPacketProgrammable.class),
-                                                  ImmutableMap.of()));
+
+        DriverRegistryManager driverRegistry = new DriverRegistryManager();
+        driverService = new TestDriverManager(driverRegistry);
+        driverRegistry.addDriver(new DefaultDriver("foo", ImmutableList.of(), "", "", "",
+                                                   ImmutableMap.of(PacketProgrammable.class,
+                                                                   TestPacketProgrammable.class),
+                                                   ImmutableMap.of()));
     }
 
     /**
@@ -140,7 +144,8 @@
     }
 
     private class TestDriverManager extends DriverManager {
-        TestDriverManager() {
+        TestDriverManager(DriverRegistry registry) {
+            this.registry = registry;
             this.deviceService = mgr.deviceService;
             activate();
         }