Restructure the public API for server

pkg/analysis_server/lib/analysis/occurrences_core.dart

Index: pkg/analysis_server/lib/analysis/occurrences_core.dart
diff --git a/pkg/analysis_server/lib/analysis/occurrences_core.dart b/pkg/analysis_server/lib/analysis/occurrences_core.dart
deleted file mode 100644
index 2e24a9b3c798093dc63cfd4e520c89f8ee211572..0000000000000000000000000000000000000000
--- a/pkg/analysis_server/lib/analysis/occurrences_core.dart
+++ /dev/null
@@ -1,35 +0,0 @@
-// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-library analysis_server.analysis.occurrences_core;
-
-import 'package:analysis_server/src/protocol.dart' show Element, Occurrences;
-import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
-import 'package:analyzer/src/generated/source.dart' show Source;
-
-/**
- * An object used to produce occurrences.
- *
- * Clients are expected to subtype this class when implementing plugins.
- */
-abstract class OccurrencesContributor {
-  /**
-   * Contribute occurrences into the given [collector].
-   * The [context] can be used to get analysis results.
-   */
-  void computeOccurrences(
-      OccurrencesCollector collector, AnalysisContext context, Source source);
-}
-
-/**
- * An object that [OccurrencesContributor]s use to record occurrences into.
- *
- * Clients are not expected to subtype this class.
- */
-abstract class OccurrencesCollector {
-  /**
-   * Record a new element occurrences.
-   */
-  void addOccurrences(Occurrences occurrences);
-}