Fix hints reported by analyzer.

pkg/compiler/lib/src/serialization/resolved_ast_serialization.dart

 // Copyright (c) 2016, 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 dart2js.serialization.resolved_ast;
 
 import '../common.dart';
 import '../common/resolution.dart';
 import '../constants/expressions.dart';
 import '../elements/resolution_types.dart';
 import '../diagnostics/diagnostic_listener.dart';
 import '../elements/elements.dart';
 import '../elements/modelx.dart';
 import '../parser/listener.dart' show ParserError;
 import '../parser/node_listener.dart' show NodeListener;
 import '../parser/parser.dart' show Parser;
 import '../resolution/enum_creator.dart';
 import '../resolution/send_structure.dart';
 import '../resolution/tree_elements.dart';
 import '../tokens/token.dart';
 import '../tree/tree.dart';
 import '../universe/selector.dart';
-import '../util/util.dart';
 import 'keys.dart';
 import 'modelz.dart';
 import 'serialization.dart';
 import 'serialization_util.dart';
 
 /// Visitor that computes a node-index mapping.
 class AstIndexComputer extends Visitor {
   final Map<Node, int> nodeIndices = <Node, int>{};
   final List<Node> nodeList = <Node>[];
 
@@ skipping 333 matching lines @@
 
   /// Deserialize the [ResolvedAst]s for the member [element] (constructor,
   /// method, or field) and its nested closures. The [ResolvedAst]s are added
   /// to [resolvedAstMap].
   static void deserializeParsed(
       AstElementMixinZ element,
       ObjectDecoder objectDecoder,
       ParsingContext parsing,
       Token getBeginToken(Uri uri, int charOffset),
       DeserializerPlugin nativeDataDeserializer) {
-    CompilationUnitElement compilationUnit = element.compilationUnit;
     DiagnosticReporter reporter = parsing.reporter;
     Uri uri = objectDecoder.getUri(Key.URI);
 
     /// Returns the first [Token] for parsing the [Node] for [element].
     Token readBeginToken() {
       int charOffset = objectDecoder.getInt(Key.OFFSET);
       Token beginToken = getBeginToken(uri, charOffset);
       if (beginToken == null) {
         // TODO(johnniwinther): Handle unfound tokens by adding an erronous
         // resolved ast kind.
         reporter.internalError(
             element, "No token found for $element in $uri @ $charOffset");
       }
       return beginToken;
     }
 
     /// Create the [Node] for the element by parsing the source code.
     Node doParse(parse(Parser parser)) {
       return parsing.measure(() {
         return reporter.withCurrentElement(element, () {
-          CompilationUnitElement unit = element.compilationUnit;
           NodeListener listener = new NodeListener(
               parsing.getScannerOptionsFor(element), reporter, null);
           listener.memberErrors = listener.memberErrors.prepend(false);
           try {
             Parser parser = new Parser(listener);
             parse(parser);
           } on ParserError catch (e) {
             reporter.internalError(element, '$e');
           }
           return listener.popNode();
         });
       });
     }
 
     /// Computes the [Node] for the element based on the [AstKind].
     Node computeNode(AstKind kind) {
       switch (kind) {
         case AstKind.ENUM_INDEX_FIELD:
           AstBuilder builder = new AstBuilder(element.sourcePosition.begin);
           Identifier identifier = builder.identifier('index');
           VariableDefinitions node = new VariableDefinitions(
               null,
               builder.modifiers(isFinal: true),
               new NodeList.singleton(identifier));
           return node;
         case AstKind.ENUM_VALUES_FIELD:
           EnumClassElement enumClass = element.enclosingClass;
           AstBuilder builder = new AstBuilder(element.sourcePosition.begin);
-          List<FieldElement> enumValues = <FieldElement>[];
           List<Node> valueReferences = <Node>[];
           for (EnumConstantElement enumConstant in enumClass.enumValues) {
             AstBuilder valueBuilder =
                 new AstBuilder(enumConstant.sourcePosition.begin);
             Identifier name = valueBuilder.identifier(enumConstant.name);
 
             // Add reference for the `values` field.
             valueReferences.add(valueBuilder.reference(name));
           }
 
@@ skipping 87 matching lines @@
           return doParse((parser) {
             parser.parseFunction(beginToken, getOrSet);
           });
       }
     }
 
     AstKind kind = objectDecoder.getEnum(Key.SUB_KIND, AstKind.values);
     Node root = computeNode(kind);
     TreeElementMapping elements = new TreeElementMapping(element);
     AstIndexComputer indexComputer = new AstIndexComputer();
-    Map<Node, int> nodeIndices = indexComputer.nodeIndices;
     List<Node> nodeList = indexComputer.nodeList;
     root.accept(indexComputer);
     elements.containsTryStatement = objectDecoder.getBool(Key.CONTAINS_TRY);
 
     Node body;
     int bodyNodeIndex = objectDecoder.getInt(Key.BODY, isOptional: true);
     if (bodyNodeIndex != null) {
       assert(invariant(element, bodyNodeIndex < nodeList.length,
           message: "Body node index ${bodyNodeIndex} out of range. "
               "Node count: ${nodeList.length}"));
@@ skipping 141 matching lines @@
         }
       }
     }
     element.resolvedAst =
         new ParsedResolvedAst(element, root, body, elements, uri);
   }
 }
 
 const Key PARAMETER_NODE = const Key('parameter.node');
 const Key PARAMETER_INITIALIZER = const Key('parameter.initializer');