estimator#afterLoad should be invoked once only per reader.

It was being invoked once per reader and parent type combination resulting in more memory being reported to the circuit breaker than actually being used in field data.

src/main/java/org/elasticsearch/index/fielddata/plain/ParentChildIndexFieldData.java

@@ -136,13 +136,13 @@ public class ParentChildIndexFieldData extends AbstractIndexFieldData<ParentChil
             } finally {
                 for (ObjectObjectCursor<String, TypeBuilder> cursor : typeBuilders) {
                     cursor.value.builder.close();
+                }
                 if (success) {
                     estimator.afterLoad(null, data.getMemorySizeInBytes());
                 }
             }
         }
     }
-    }
 
     @Override
     public void beforeCreate(DocumentMapper mapper) {