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/AbstractDriverLoader.java b/core/api/src/main/java/org/onosproject/net/driver/AbstractDriverLoader.java
index 7899d0c..1374044 100644
--- a/core/api/src/main/java/org/onosproject/net/driver/AbstractDriverLoader.java
+++ b/core/api/src/main/java/org/onosproject/net/driver/AbstractDriverLoader.java
@@ -26,6 +26,9 @@
 @Component
 public abstract class AbstractDriverLoader extends AbstractIndependentDriverLoader {
 
+    // FIXME: This requirement should be removed and the driver extensions that
+    // depend on the default drivers being loaded should be modified to instead
+    // express the dependency using the application dependency mechanism.
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected DefaultDriverProviderService defaultDriverProviderService;