Fix some strong mode issues.

test/class_hierarchy_tester.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.
 
 import 'package:kernel/kernel.dart';
 import 'package:kernel/class_hierarchy.dart';
 import 'package:test/test.dart';
 import 'class_hierarchy_basic.dart';
 import 'dart:io';
 import 'dart:math';
@@ skipping 34 matching lines @@
   }
   Set<Name> names = new Set<Name>();
   for (var classNode in classHierarchy.classes) {
     for (var member in classNode.members) {
       names.add(member.name);
     }
   }
   List<Name> nameList = names.toList();
   progress = 0;
   for (var classNode in classHierarchy.classes) {
-    Iterable<Name> candidateNames = [
+    Iterable<Name> candidateNames = <Iterable<Name>>[
       basic.gettersAndCalls[classNode].keys,
       basic.setters[classNode].keys,
       pickRandom(nameList, 100)
     ].expand((x) => x);
     for (Name name in candidateNames) {
       Member expectedGetter =
           basic.getDispatchTarget(classNode, name, setter: false);
       Member expectedSetter =
           basic.getDispatchTarget(classNode, name, setter: true);
       Member actualGetter =
@@ skipping 68 matching lines @@
       }
     }
   }
   if (verbose) {
     print('\rProgress 100%. Done.');
   }
 }
 
 var random = new Random(12345);
 
-List pickRandom(List items, int n) {
-  var result = [];
+List/*<T>*/ pickRandom/*<T>*/(List/*<T>*/ items, int n) {
+  var result = /*<T>*/[];
   for (int i = 0; i < n; ++i) {
     result.add(items[random.nextInt(items.length)]);
   }
   return result;
 }