Revert "Revert "Make ClosureTask only accept Element-level APIs instead of resolvedAst.""

tests/compiler/dart2js/serialization/model_test_helper.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 'package:async_helper/async_helper.dart';
 import 'package:expect/expect.dart';
 import 'package:compiler/src/closure.dart';
@@ skipping 142 matching lines @@
   });
 }
 
 void checkElements(
     Compiler compiler1, Compiler compiler2, Element element1, Element element2,
     {bool verbose: false}) {
   if (element1.isAbstract) return;
   if (element1.isFunction ||
       element1.isConstructor ||
       (element1.isField && element1.isInstanceMember)) {
     AstElement astElement1 = element1;

[Siggi Cherem (dart-lang), 2017/06/05 22:27:04]

you might be able to delete these locals now.

[Emily Fortuna, 2017/06/05 22:30:21]

oh good point! Thanks.

     AstElement astElement2 = element2;
-    ClosureClassMap closureData1 = compiler1.closureToClassMapper
-        .getClosureToClassMapping(astElement1.resolvedAst);
-    ClosureClassMap closureData2 = compiler2.closureToClassMapper
-        .getClosureToClassMapping(astElement2.resolvedAst);
+    ClosureClassMap closureData1 =
+        compiler1.closureToClassMapper.getClosureToClassMapping(element1);
+    ClosureClassMap closureData2 =
+        compiler2.closureToClassMapper.getClosureToClassMapping(element2);
 
     checkElementIdentities(
         closureData1,
         closureData2,
         '$element1.closureElement',
         closureData1.closureElement,
         closureData2.closureElement);
     checkElementIdentities(
         closureData1,
         closureData2,
@@ skipping 117 matching lines @@
   check(outputUnit1, outputUnit2, 'OutputUnit.isMainOutput $message',
       outputUnit1.isMainOutput, outputUnit2.isMainOutput);
   checkSetEquivalence(
       outputUnit1,
       outputUnit2,
       'OutputUnit.imports $message',
       outputUnit1.imports,
       outputUnit2.imports,
       (a, b) => areElementsEquivalent(a.declaration, b.declaration));
 }