Remove most of the remaining references to AnalysisContext

pkg/analysis_server/lib/plugin/analysis/occurrences/occurrences_core.dart

Index: pkg/analysis_server/lib/plugin/analysis/occurrences/occurrences_core.dart
diff --git a/pkg/analysis_server/lib/plugin/analysis/occurrences/occurrences_core.dart b/pkg/analysis_server/lib/plugin/analysis/occurrences/occurrences_core.dart
index 3d3a7f3898f71f20b83b641e1d86e338026756d2..22a85fd8135f197416a61b49d71d94f7bb303518 100644
--- a/pkg/analysis_server/lib/plugin/analysis/occurrences/occurrences_core.dart
+++ b/pkg/analysis_server/lib/plugin/analysis/occurrences/occurrences_core.dart
@@ -2,12 +2,10 @@
 // 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.
 
-import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
-import 'package:analyzer/src/generated/source.dart' show Source;
 import 'package:analyzer_plugin/protocol/protocol_common.dart' show Occurrences;
 
 /**
- * An object that [OccurrencesContributor]s use to record occurrences into.
+ * An object used to record occurrences into.
  *
  * Clients may not extend, implement or mix-in this class.
  */
@@ -17,17 +15,3 @@ abstract class OccurrencesCollector {
    */
   void addOccurrences(Occurrences occurrences);
 }
-
-/**
- * An object used to produce occurrences.
- *
- * Clients may implement 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);
-}