Add batched merge results size estimations to CB

Author: ivancea

server/src/main/java/org/elasticsearch/action/search/QueryPhaseResultConsumer.java

@@ -231,6 +231,7 @@ public SearchPhaseController.ReducedQueryPhase reduce() throws Exception {
  while ((batchedResult = batchedResults.poll()) != null) {
  topDocsStats.add(batchedResult.v1());
  consumePartialMergeResult(batchedResult.v2(), topDocsList, aggsList);
+ addEstimateAndMaybeBreak(batchedResult.v2().estimatedSize);
  }
  for (QuerySearchResult result : buffer) {
  topDocsStats.add(result.topDocs(), result.searchTimedOut(), result.terminatedEarly());
@@ -392,7 +393,7 @@ private MergeResult partialReduce(
  return new MergeResult(
  processedShards,
  newTopDocs,
- newAggs == null ? null : DelayableWriteable.referencing(newAggs),
+ newAggs != null ? DelayableWriteable.referencing(newAggs) : null,
  newAggs != null ? DelayableWriteable.getSerializedSize(newAggs) : 0
  );
  }