Element no longer implements AnalysisTarget

pkg/analyzer/lib/src/task/dart.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 analyzer.src.task.dart;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
@@ skipping 1806 matching lines @@
     // all of the constructor initializers that we might encounter have been
     // copied into the element model. We tried forcing the computation of the
     // RESOLVED_UNIT9 for each unit reachable from the target's library, but
     // that had too big a performance impact. We could potentially mitigate the
     // impact by computing a more accurate list of the sources containing
     // constructors that are actually referenced, but other approaches should
     // be considered.
     //
     Source librarySource;
     if (target is Element) {
-      CompilationUnitElementImpl unit = target
+      Element elt = target as Element;

[Brian Wilkerson, 2016/02/01 15:43:20]

This shouldn't be necessary because of type propagation.

+      CompilationUnitElementImpl unit = elt
           .getAncestor((Element element) => element is CompilationUnitElement);
       librarySource = unit.librarySource;
     } else if (target is ConstantEvaluationTarget_Annotation) {
       librarySource = target.librarySource;
     } else {
       throw new AnalysisException(
           'Cannot build inputs for a ${target.runtimeType}');
     }
     return <String, TaskInput>{
       'resolvedUnit': RESOLVED_UNIT10
@@ skipping 3640 matching lines @@
 
   @override
   bool moveNext() {
     if (_newSources.isEmpty) {
       return false;
     }
     currentTarget = _newSources.removeLast();
     return true;
   }
 }