Use IndexContributor(s) in LocalIndex.

pkg/analysis_server/lib/analysis/index_core.dart

Index: pkg/analysis_server/lib/analysis/index_core.dart
diff --git a/pkg/analysis_server/lib/analysis/index/index_core.dart b/pkg/analysis_server/lib/analysis/index_core.dart
similarity index 97%
rename from pkg/analysis_server/lib/analysis/index/index_core.dart
rename to pkg/analysis_server/lib/analysis/index_core.dart
index 81d232d8b2da36efd16a00916173d77a1437daeb..aac9d8a303bc800df776a0c824d761cdeccde080 100644
--- a/pkg/analysis_server/lib/analysis/index/index_core.dart
+++ b/pkg/analysis_server/lib/analysis/index_core.dart
@@ -115,10 +115,10 @@ abstract class IndexableObjectKind {
  */
 abstract class IndexContributor {
   /**
-   * Contribute relationships to the given index [store] as a result of
-   * analyzing the given [source] in the given [context].
+   * Contribute relationships existing in the given [object] to the given
+   * index [store] in the given [context].
    */
-  void contributeTo(IndexStore store, AnalysisContext context, Source source);
+  void contributeTo(IndexStore store, AnalysisContext context, Object object);
 }
 
 // A sketch of what the driver routine might look like: