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

pkg/compiler/lib/src/ssa/kernel_ast_adapter.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:js_runtime/shared/embedded_names.dart';
 import 'package:kernel/ast.dart' as ir;
 
 import '../closure.dart';
 import '../common.dart';
 import '../compiler.dart';
@@ skipping 98 matching lines @@
     if (originTarget is MethodElement) {
       if (originTarget is ConstructorBodyElement) {
         ConstructorBodyElement body = originTarget;
         originTarget = body.constructor;
       }
       target = kernel.functions[originTarget];
       // Closures require a lookup one level deeper in the closure class mapper.
       if (target == null) {
         MethodElement originTargetFunction = originTarget;
         ClosureClassMap classMap = _compiler.closureToClassMapper
-            .getClosureToClassMapping(originTargetFunction.resolvedAst);
+            .getClosureToClassMapping(originTargetFunction);
         if (classMap.closureElement != null) {
           target = kernel.localFunctions[classMap.closureElement];
         }
       }
     } else if (originTarget is FieldElement) {
       target = kernel.fields[originTarget];
     }
     assert(target != null);
     return target;
   }
@@ skipping 502 matching lines @@
   TypeMask selectorTypeOf(Selector selector, TypeMask mask) {
     return TypeMaskFactory.inferredTypeForSelector(
         selector, mask, _globalInferenceResults);
   }
 
   TypeMask typeFromNativeBehavior(
       native.NativeBehavior nativeBehavior, ClosedWorld closedWorld) {
     return TypeMaskFactory.fromNativeBehavior(nativeBehavior, closedWorld);
   }
 }