Store ResolvedAst on AstElement

tests/compiler/dart2js/serialization/model_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 dart2js.serialization_model_test;
 
 import 'dart:async';
 import 'dart:io';
 import 'package:async_helper/async_helper.dart';
 import 'package:expect/expect.dart';
@@ skipping 120 matching lines @@
       verbose: verbose);
 }
 
 void checkElements(
     Compiler compiler1, Compiler compiler2,
     Element element1, Element element2,
     {bool verbose: false}) {
   if (element1.isFunction ||
       element1.isConstructor ||
       (element1.isField && element1.isInstanceMember)) {
+    AstElement astElement1 = element1;
+    AstElement astElement2 = element2;
     ClosureClassMap closureData1 =
     compiler1.closureToClassMapper.computeClosureToClassMapping(
-        compiler1.backend.frontend.getResolvedAst(element1.declaration));
+        astElement1.resolvedAst);
     ClosureClassMap closureData2 =
     compiler2.closureToClassMapper.computeClosureToClassMapping(
-        compiler2.backend.frontend.getResolvedAst(element2.declaration));
+        astElement2.resolvedAst);
 
     checkElementIdentities(closureData1, closureData2,
         '$element1.closureElement',
         closureData1.closureElement, closureData2.closureElement);
     checkElementIdentities(closureData1, closureData2,
         '$element1.closureClassElement',
         closureData1.closureClassElement, closureData2.closureClassElement);
     checkElementIdentities(closureData1, closureData2,
         '$element1.callElement',
         closureData1.callElement, closureData2.callElement);
@@ skipping 243 matching lines @@
   return true;
 }
 
 String nodeToString(Node node) {
   String text = '$node';
   if (text.length > 40) {
     return '(${node.runtimeType}) ${text.substring(0, 37)}...';
   }
   return '(${node.runtimeType}) $text';
 }