Validation of the reducer factories is now called from within the AggregatorFactories

src/main/java/org/elasticsearch/search/aggregations/AggregatorFactories.java

@@ -106,6 +106,9 @@ public class AggregatorFactories {
         for (AggregatorFactory factory : factories) {
             factory.validate();
         }
+        for (ReducerFactory factory : reducerFactories) {
+            factory.validate();
+        }
     }
 
     private final static class Empty extends AggregatorFactories {

src/main/java/org/elasticsearch/search/aggregations/reducers/ReducerFactory.java

@@ -49,7 +49,7 @@ public abstract class ReducerFactory {
     /**
      * Validates the state of this factory (makes sure the factory is properly configured)
      */
-    public final void validate() { // NOCOMMIT hook in validation 
+    public final void validate() {
         doValidate();
     }