Revert collecting defined elements.

pkg/analyzer/lib/src/generated/resolver.dart

 // Copyright (c) 2014, 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.
 
 library analyzer.src.generated.resolver;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 3997 matching lines @@
     for (int i = 0; i < count; i++) {
       annotations[i].accept(this);
     }
   }
 }
 
 /**
  * An [AstVisitor] that fills [UsedLocalElements].
  */
 class GatherUsedLocalElementsVisitor extends RecursiveAstVisitor {
-  final List<Element> definedElements = <Element>[];
   final UsedLocalElements usedElements = new UsedLocalElements();
 
   final LibraryElement _enclosingLibrary;
   ClassElement _enclosingClass;
   ExecutableElement _enclosingExec;
 
   GatherUsedLocalElementsVisitor(this._enclosingLibrary);
 
   @override
   visitCatchClause(CatchClause node) {
@@ skipping 49 matching lines @@
     try {
       _enclosingExec = node.element;
       super.visitMethodDeclaration(node);
     } finally {
       _enclosingExec = enclosingExecOld;
     }
   }
 
   @override
   visitSimpleIdentifier(SimpleIdentifier node) {
-    Element element = node.staticElement;
     if (node.inDeclarationContext()) {
-      if (element != null) {
-        definedElements.add(element);
-      }
       return;
     }
+    Element element = node.staticElement;
     bool isIdentifierRead = _isReadIdentifier(node);
     if (element is LocalVariableElement) {
       if (isIdentifierRead) {
         usedElements.addElement(element);
       }
     } else {
       _useIdentifierElement(node);
       if (element == null ||
           element.enclosingElement is ClassElement &&
               !identical(element, _enclosingExec)) {
@@ skipping 8125 matching lines @@
     }
     return false;
   }
 }
 
 /**
  * Instances of the class [UnusedLocalElementsVerifier] traverse an element
  * structure looking for cases of [HintCode.UNUSED_ELEMENT],
  * [HintCode.UNUSED_FIELD], [HintCode.UNUSED_LOCAL_VARIABLE], etc.
  */
-class UnusedLocalElementsVerifier extends SimpleElementVisitor {
+class UnusedLocalElementsVerifier extends RecursiveElementVisitor {
   /**
    * The error listener to which errors will be reported.
    */
   final AnalysisErrorListener _errorListener;
 
   /**
    * The elements know to be used.
    */
   final UsedLocalElements _usedElements;
 
@@ skipping 549 matching lines @@
     nonFields.add(node);
     return null;
   }
 
   @override
   Object visitNode(AstNode node) => node.accept(TypeResolverVisitor_this);
 
   @override
   Object visitWithClause(WithClause node) => null;
 }