Refining driver subsystem to facilitate coordinated start-up.

- for ONOS-6402

Change-Id: I7f64fc62ad1d451fcf55624b2422b60631a3c8e8
diff --git a/core/api/src/main/java/org/onosproject/net/driver/DriverRegistry.java b/core/api/src/main/java/org/onosproject/net/driver/DriverRegistry.java
new file mode 100644
index 0000000..75211b5
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/driver/DriverRegistry.java
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2017-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.net.driver;
+
+import java.util.Set;
+
+/**
+ * Service for obtaining drivers and driver behaviour implementations.
+ */
+public interface DriverRegistry extends DriverPrimordialResolver, DriverResolver {
+
+    /**
+     * Returns the overall set of drivers being provided.
+     *
+     * @return provided drivers
+     */
+    Set<Driver> getDrivers();
+
+}