extract LabelContributor from local reference contributor

pkg/analysis_server/lib/src/services/completion/local_reference_contributor.dart

Index: pkg/analysis_server/lib/src/services/completion/local_reference_contributor.dart
diff --git a/pkg/analysis_server/lib/src/services/completion/local_reference_contributor.dart b/pkg/analysis_server/lib/src/services/completion/local_reference_contributor.dart
index 6753a400f85c1ec0fec3f1daa767a0ed1483d165..23282d04bc9c3618cfa390b95a6aad850a90e350 100644
--- a/pkg/analysis_server/lib/src/services/completion/local_reference_contributor.dart
+++ b/pkg/analysis_server/lib/src/services/completion/local_reference_contributor.dart
@@ -41,14 +41,6 @@ class LocalReferenceContributor extends DartCompletionContributor {
             new _LocalVisitor(request, request.offset, optype);
         localVisitor.visit(request.target.containingNode);
       }
-      if (optype.includeStatementLabelSuggestions ||
-          optype.includeCaseLabelSuggestions) {
-        _LabelVisitor labelVisitor = new _LabelVisitor(
-            request,
-            optype.includeStatementLabelSuggestions,
-            optype.includeCaseLabelSuggestions);
-        labelVisitor.visit(request.target.containingNode);
-      }
       if (optype.includeConstructorSuggestions) {
         new _ConstructorVisitor(request).visit(request.target.containingNode);
       }
@@ -238,119 +230,6 @@ class _ConstructorVisitor extends LocalDeclarationVisitor {
 }
 
 /**
- * A visitor for collecting suggestions for break and continue labels.
- */
-class _LabelVisitor extends LocalDeclarationVisitor {
-  final DartCompletionRequest request;
-
-  /**
-   * True if statement labels should be included as suggestions.
-   */
-  final bool includeStatementLabels;
-
-  /**
-   * True if case labels should be included as suggestions.
-   */
-  final bool includeCaseLabels;
-
-  _LabelVisitor(DartCompletionRequest request, this.includeStatementLabels,
-      this.includeCaseLabels)
-      : super(request.offset),
-        request = request;
-
-  @override
-  void declaredClass(ClassDeclaration declaration) {
-    // ignored
-  }
-
-  @override
-  void declaredClassTypeAlias(ClassTypeAlias declaration) {
-    // ignored
-  }
-
-  @override
-  void declaredField(FieldDeclaration fieldDecl, VariableDeclaration varDecl) {
-    // ignored
-  }
-
-  @override
-  void declaredFunction(FunctionDeclaration declaration) {
-    // ignored
-  }
-
-  @override
-  void declaredFunctionTypeAlias(FunctionTypeAlias declaration) {
-    // ignored
-  }
-
-  @override
-  void declaredLabel(Label label, bool isCaseLabel) {
-    if (isCaseLabel ? includeCaseLabels : includeStatementLabels) {
-      CompletionSuggestion suggestion = _addSuggestion(label.label);
-      if (suggestion != null) {
-        suggestion.element = createElement(
-            request.source, protocol.ElementKind.LABEL, label.label,
-            returnType: NO_RETURN_TYPE);
-      }
-    }
-  }
-
-  @override
-  void declaredLocalVar(SimpleIdentifier name, TypeName type) {
-    // ignored
-  }
-
-  @override
-  void declaredMethod(MethodDeclaration declaration) {
-    // ignored
-  }
-
-  @override
-  void declaredParam(SimpleIdentifier name, TypeName type) {
-    // ignored
-  }
-
-  @override
-  void declaredTopLevelVar(
-      VariableDeclarationList varList, VariableDeclaration varDecl) {
-    // ignored
-  }
-
-  @override
-  void visitFunctionExpression(FunctionExpression node) {
-    // Labels are only accessible within the local function, so stop visiting
-    // once we reach a function boundary.
-    finished();
-  }
-
-  @override
-  void visitMethodDeclaration(MethodDeclaration node) {
-    // Labels are only accessible within the local function, so stop visiting
-    // once we reach a function boundary.
-    finished();
-  }
-
-  CompletionSuggestion _addSuggestion(SimpleIdentifier id) {
-    if (id != null) {
-      String completion = id.name;
-      if (completion != null && completion.length > 0 && completion != '_') {
-        CompletionSuggestion suggestion = new CompletionSuggestion(
-            CompletionSuggestionKind.IDENTIFIER,
-            DART_RELEVANCE_DEFAULT,
-            completion,
-            completion.length,
-            0,
-            false,
-            false);
-        request.addSuggestion(suggestion);
-        return suggestion;
-      }
-    }
-    return null;
-  }
-}
-
-/**
  * A visitor for collecting suggestions from the most specific child [AstNode]
  * that contains the completion offset to the [CompilationUnit].
  */