Record HAS_ANCESTOR relations into index.

pkg/analysis_server/test/services/search/search_engine_test.dart

Index: pkg/analysis_server/test/services/search/search_engine_test.dart
diff --git a/pkg/analysis_server/test/services/search/search_engine_test.dart b/pkg/analysis_server/test/services/search/search_engine_test.dart
index 3e411d22e0aa81d88a9ae2cc588c3c1ac4915870..1453d466b34e84d0e057a318b1dbfab02f1efea7 100644
--- a/pkg/analysis_server/test/services/search/search_engine_test.dart
+++ b/pkg/analysis_server/test/services/search/search_engine_test.dart
@@ -77,6 +77,27 @@ class SearchEngineImplTest extends AbstractSingleUnitTest {
     searchEngine = new SearchEngineImpl(index);
   }
 
+  Future test_searchAllSubtypes() {
+    _indexTestUnit('''
+class T {}
+class A extends T {}
+class B extends A {}
+class C implements B {}
+''');
+    ClassElement element = findElement('T');
+    ClassElement elementA = findElement('A');
+    ClassElement elementB = findElement('B');
+    ClassElement elementC = findElement('C');
+    var expected = [
+      _expectId(elementA, MatchKind.DECLARATION, 'A extends T'),
+      _expectId(elementB, MatchKind.DECLARATION, 'B extends A'),
+      _expectId(elementC, MatchKind.DECLARATION, 'C implements B')
+    ];
+    return searchEngine.searchAllSubtypes(element).then((matches) {
+      _assertMatches(matches, expected);
+    });
+  }
+
   Future test_searchElementDeclarations() {
     _indexTestUnit('''
 class A {