Remove uses of the old plugin model from the analysis server

pkg/analysis_server/lib/src/domains/analysis/occurrences.dart

Index: pkg/analysis_server/lib/src/domains/analysis/occurrences.dart
diff --git a/pkg/analysis_server/lib/src/domains/analysis/occurrences.dart b/pkg/analysis_server/lib/src/domains/analysis/occurrences.dart
index d483b8475d6666560d1674ec87eabe459d9dbbc5..3862078c0e0ab6f8a36dd9de179dc9ddee96cac0 100644
--- a/pkg/analysis_server/lib/src/domains/analysis/occurrences.dart
+++ b/pkg/analysis_server/lib/src/domains/analysis/occurrences.dart
@@ -3,32 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:analysis_server/plugin/analysis/occurrences/occurrences_core.dart';
-import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/protocol_server.dart' as protocol;
-import 'package:analyzer/exception/exception.dart';
-import 'package:analyzer/src/generated/engine.dart'
-    show AnalysisContext, AnalysisEngine;
-import 'package:analyzer/src/generated/source.dart' show Source;
-
-/**
- * Compute all known occurrences for the given [source].
- */
-OccurrencesCollectorImpl computeOccurrences(
-    AnalysisServer server, AnalysisContext context, Source source) {
-  OccurrencesCollectorImpl collector = new OccurrencesCollectorImpl();
-  List<OccurrencesContributor> contributors =
-      server.serverPlugin.occurrencesContributors;
-  for (OccurrencesContributor contributor in contributors) {
-    try {
-      contributor.computeOccurrences(collector, context, source);
-    } catch (exception, stackTrace) {
-      AnalysisEngine.instance.logger.logError(
-          'Exception from occurrences contributor: ${contributor.runtimeType}',
-          new CaughtException(exception, stackTrace));
-    }
-  }
-  return collector;
-}
 
 /**
  * A concrete implementation of [OccurrencesCollector].