More steps toward making server strong mode clean

pkg/analysis_server/lib/src/search/element_references.dart

Index: pkg/analysis_server/lib/src/search/element_references.dart
diff --git a/pkg/analysis_server/lib/src/search/element_references.dart b/pkg/analysis_server/lib/src/search/element_references.dart
index 74c72ef4ba2a86d1e96ecb29ff3842ed2bab81b3..30ae4222da585e406f97b4fec97934731dce5121 100644
--- a/pkg/analysis_server/lib/src/search/element_references.dart
+++ b/pkg/analysis_server/lib/src/search/element_references.dart
@@ -64,12 +64,10 @@ class ElementReferencesComputer {
   /**
    * Returns a [Future] completing with a [List] of references to [element].
    */
-  Future<List<SearchResult>> _findSingleElementReferences(Element element) {
-    Future<List<SearchMatch>> matchesFuture =
-        searchEngine.searchReferences(element);
-    return matchesFuture.then((List<SearchMatch> matches) {
-      return matches.map(toResult).toList();
-    });
+  Future<List<SearchResult>> _findSingleElementReferences(
+      Element element) async {
+    List<SearchMatch> matches = await searchEngine.searchReferences(element);
+    return matches.map(toResult).toList();
   }
 
   /**