Fix recently introduced strong-mode errors

pkg/analyzer/test/src/task/dart_test.dart

 // Copyright (c) 2015, 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.test.src.task.dart_test;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 163 matching lines @@
 @x
 f() {
   const z = 1;
 }
 ''');
     CompilationUnit unit = outputs[RESOLVED_UNIT1];
     CompilationUnitElement unitElement = outputs[COMPILATION_UNIT_ELEMENT];
     Annotation annotation = unit.declarations
         .firstWhere((m) => m is FunctionDeclaration)
         .metadata[0];
-    List<ConstantEvaluationTarget> expectedConstants = [
+    List<ConstantEvaluationTarget> expectedConstants =

[Jennifer Messerly, 2016/09/15 21:00:33]

maybe "var" on left side so the type isn't repeated? and would fit on one line
:)

[Brian Wilkerson, 2016/09/15 21:37:26]

I would, but there is a sharp pain in the back of my head every time I type that
three letter replacement for a type. :-)

+        <ConstantEvaluationTarget>[
       unitElement.accessors.firstWhere((e) => e.isGetter).variable,
       unitElement.types[0].fields[0],
       unitElement.functions[0].localVariables[0],
       unitElement.types[0].constructors[0],
       annotation.elementAnnotation,
       unitElement.types[0].constructors[0].parameters[0]
     ];
     expect(
         outputs[COMPILATION_UNIT_CONSTANTS].toSet(), expectedConstants.toSet());
   }
@@ skipping 5348 matching lines @@
   /**
    * Fill [errorListener] with [result] errors in the current [task].
    */
   void _fillErrorListener(ResultDescriptor<List<AnalysisError>> result) {
     List<AnalysisError> errors = task.outputs[result] as List<AnalysisError>;
     expect(errors, isNotNull, reason: result.name);
     errorListener = new GatheringErrorListener();
     errorListener.addAll(errors);
   }
 }