Move LocalDeclarationVisitor for use by contributors that will be moved to analyzer_plugin

pkg/analyzer_plugin/lib/src/utilities/visitors/local_declaration_visitor.dart

Index: pkg/analyzer_plugin/lib/src/utilities/visitors/local_declaration_visitor.dart
diff --git a/pkg/analysis_server/lib/src/services/completion/dart/local_declaration_visitor.dart b/pkg/analyzer_plugin/lib/src/utilities/visitors/local_declaration_visitor.dart
similarity index 96%
rename from pkg/analysis_server/lib/src/services/completion/dart/local_declaration_visitor.dart
rename to pkg/analyzer_plugin/lib/src/utilities/visitors/local_declaration_visitor.dart
index 548f2791564357ed0a60202fc724700a0e354ac0..8dafe81ab4e9fb3e8b4e57e97983d97f149acf66 100644
--- a/pkg/analysis_server/lib/src/services/completion/dart/local_declaration_visitor.dart
+++ b/pkg/analyzer_plugin/lib/src/utilities/visitors/local_declaration_visitor.dart
@@ -1,4 +1,4 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2017, 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.
 
@@ -9,9 +9,9 @@ import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/src/dart/ast/token.dart';
 
 /**
- * `LocalDeclarationCollector` visits an [AstNode] and its parent recursively
- * along with any declarations in those nodes. Consumers typically call [visit]
- * which catches the exception thrown by [finished()].
+ * A visitor that visits an [AstNode] and its parent recursively along with any
+ * declarations in those nodes. Consumers typically call [visit] which catches
+ * the exception thrown by [finished].
  */
 abstract class LocalDeclarationVisitor extends GeneralizingAstVisitor {
   static final TypeName STACKTRACE_TYPE = astFactory.typeName(