Search for direct and indirect subclasses.

pkg/analysis_server/lib/src/services/search/search_engine_internal2.dart

Index: pkg/analysis_server/lib/src/services/search/search_engine_internal2.dart
diff --git a/pkg/analysis_server/lib/src/services/search/search_engine_internal2.dart b/pkg/analysis_server/lib/src/services/search/search_engine_internal2.dart
index 9ae8a0a68f1198fdbe090b4c59e00ae751f46c26..4b179bcd7f32fcc4790af36c5f6b2bc4dc4a3d87 100644
--- a/pkg/analysis_server/lib/src/services/search/search_engine_internal2.dart
+++ b/pkg/analysis_server/lib/src/services/search/search_engine_internal2.dart
@@ -28,9 +28,11 @@ class SearchEngineImpl2 implements SearchEngine {
   SearchEngineImpl2(this.context, this._index);
 
   @override
-  Future<List<SearchMatch>> searchAllSubtypes(ClassElement type) {
-    // TODO: implement searchAllSubtypes
-    throw new UnimplementedError();
+  Future<List<SearchMatch>> searchAllSubtypes(ClassElement type) async {
+    List<SearchMatch> matches = <SearchMatch>[];
+    await _addMatches(
+        matches, type, IndexRelationKind.IS_ANCESTOR_OF, MatchKind.DECLARATION);
+    return matches;
   }
 
   @override
@@ -81,9 +83,15 @@ class SearchEngineImpl2 implements SearchEngine {
   }
 
   @override
-  Future<List<SearchMatch>> searchSubtypes(ClassElement type) {
-    // TODO: implement searchSubtypes
-    throw new UnimplementedError();
+  Future<List<SearchMatch>> searchSubtypes(ClassElement type) async {
+    List<SearchMatch> matches = <SearchMatch>[];
+    await _addMatches(
+        matches, type, IndexRelationKind.IS_EXTENDED_BY, MatchKind.REFERENCE);
+    await _addMatches(
+        matches, type, IndexRelationKind.IS_MIXED_IN_BY, MatchKind.REFERENCE);
+    await _addMatches(matches, type, IndexRelationKind.IS_IMPLEMENTED_BY,
+        MatchKind.REFERENCE);
+    return matches;
   }
 
   @override