Update mock sdk to fix test

test/checker/inferred_type_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.
 
 /// Tests for type inference.
 library dev_compiler.test.inferred_type_test;
 
 import 'package:unittest/unittest.dart';
 
 import 'package:dev_compiler/src/testing.dart';
@@ skipping 605 matching lines @@
         }
 
         var map = <String, Foo>{};
         // Error: map must be an Iterable.
         for (var x in /*severe:StaticTypeError*/map) {
           String y = /*info:DynamicCast*/x;
         }
 
         // We're not properly inferring that map.keys is an Iterable<String>
         // and that x is a String.
-        for (var x in /*info:DynamicCast should be pass*/map.keys) {
-          String y = /*info:DynamicCast should be pass*/x;
+        for (var x in map.keys) {
+          String y = x;
         }
       }
       '''
     });
 
     // for loop, with inference
     testChecker({
       '/main.dart': '''
       test() {
         for (var i = 0; i < 10; i++) {
@@ skipping 570 matching lines @@
           static final T foo = m1(m2(m3('', '')));
           static T m1(String m) { return null; }
           static String m2(e) { return ''; }
         }
 
 
     '''
     }, inferFromOverrides: true, inferTransitively: true);
   });
 }