Make index provisional API.

pkg/analysis_server/test/services/index/dart_index_contributor_test.dart

Index: pkg/analysis_server/test/services/index/dart_index_contributor_test.dart
diff --git a/pkg/analysis_server/test/services/index/dart_index_contributor_test.dart b/pkg/analysis_server/test/services/index/dart_index_contributor_test.dart
index 1830a285943c337c44bc75d23d0030ba990dc406..9ba6cae2f5cbb2b74559cb8e98893b540c8a3e0a 100644
--- a/pkg/analysis_server/test/services/index/dart_index_contributor_test.dart
+++ b/pkg/analysis_server/test/services/index/dart_index_contributor_test.dart
@@ -4,7 +4,7 @@
 
 library test.services.src.index.dart_index_contributor;
 
-import 'package:analysis_server/plugin/index/index_core.dart';
+import 'package:analysis_server/src/provisional/index/index_core.dart';
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analysis_server/src/services/index/index_contributor.dart';
 import 'package:analysis_server/src/services/index/index_store.dart';
@@ -94,27 +94,6 @@ class DartUnitContributorTest extends AbstractSingleUnitTest {
     });
   }
 
-  void test_isReferencedBy_PrefixElement() {
-    _indexTestUnit('''
-import 'dart:async' as ppp;
-main() {
-  ppp.Future a;
-  ppp.Stream b;
-}
-''');
-    // prepare elements
-    PrefixElement element = findNodeElementAtString('ppp;');
-    Element elementA = findElement('a');
-    Element elementB = findElement('b');
-    IndexableElement indexable = new IndexableElement(element);
-    // verify
-    _assertRecordedRelation(indexable, IndexConstants.IS_REFERENCED_BY,
-        _expectedLocation(elementA, 'ppp.Future'));
-    _assertRecordedRelation(indexable, IndexConstants.IS_REFERENCED_BY,
-        _expectedLocation(elementB, 'ppp.Stream'));
-    _assertNoRecordedRelation(indexable, null, _expectedLocation(null, 'ppp;'));
-  }
-
   void test_bad_unresolvedFieldFormalParameter() {
     verifyNoTestUnitErrors = false;
     _indexTestUnit('''
@@ -1423,6 +1402,27 @@ main() {
         _expectedLocation(mainElement, 'p: 1'));
   }
 
+  void test_isReferencedBy_PrefixElement() {
+    _indexTestUnit('''
+import 'dart:async' as ppp;
+main() {
+  ppp.Future a;
+  ppp.Stream b;
+}
+''');
+    // prepare elements
+    PrefixElement element = findNodeElementAtString('ppp;');
+    Element elementA = findElement('a');
+    Element elementB = findElement('b');
+    IndexableElement indexable = new IndexableElement(element);
+    // verify
+    _assertRecordedRelation(indexable, IndexConstants.IS_REFERENCED_BY,
+        _expectedLocation(elementA, 'ppp.Future'));
+    _assertRecordedRelation(indexable, IndexConstants.IS_REFERENCED_BY,
+        _expectedLocation(elementB, 'ppp.Stream'));
+    _assertNoRecordedRelation(indexable, null, _expectedLocation(null, 'ppp;'));
+  }
+
   void test_isReferencedBy_TopLevelVariableElement() {
     addSource(
         '/lib.dart',