Make server use the common protocol classes

pkg/analysis_server/lib/plugin/analysis/navigation/navigation_core.dart

Index: pkg/analysis_server/lib/plugin/analysis/navigation/navigation_core.dart
diff --git a/pkg/analysis_server/lib/plugin/analysis/navigation/navigation_core.dart b/pkg/analysis_server/lib/plugin/analysis/navigation/navigation_core.dart
index c41bce539219ce216293cd004288a18b3f6c5ff4..5a1c18dca03580f03cd7c9c636a79564d1b30766 100644
--- a/pkg/analysis_server/lib/plugin/analysis/navigation/navigation_core.dart
+++ b/pkg/analysis_server/lib/plugin/analysis/navigation/navigation_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.
 
-library analysis_server.plugin.analysis.navigation.navigation_core;
-
-import 'package:analysis_server/protocol/protocol_generated.dart'
-    show ElementKind, Location;
 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 ElementKind, Location;
 
 /**
  * An object that [NavigationContributor]s use to record navigation regions.