Handle function-typed field initializer arguments.

dart/lib/compiler/implementation/closure.dart

 // Copyright (c) 2012, 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("closureToClassMapper");
 
 #import("elements/elements.dart");
 #import("leg.dart");
 #import("scanner/scannerlib.dart");
 #import("tree/tree.dart");
@@ skipping 294 matching lines @@
     for (Link<Node> link = node.definitions.nodes;
          !link.isEmpty();
          link = link.tail) {
       Node definition = link.head;
       Element element = elements[definition];
       assert(element !== null);
       declareLocal(element);
       // We still need to visit the right-hand sides of the init-assignments.
       // For SendSets don't visit the left again. Otherwise it would be marked
       // as mutated.
-      if (definition is SendSet) {
-        SendSet assignment = definition;
-        visit(assignment.argumentsNode);
+      if (definition is Send) {
+        Send assignment = definition;
+        Node arguments = assignment.argumentsNode;
+        if (arguments != null) {
+          visit(arguments);
+        }
       } else {
         visit(definition);
       }
     }
   }
 
   visitIdentifier(Identifier node) {
     if (node.isThis()) {
       useLocal(closureData.thisElement);
     }
@@ skipping 294 matching lines @@
   }
 
   visitTryStatement(TryStatement node) {
     // TODO(ngeoffray): implement finer grain state.
     bool oldInTryStatement = inTryStatement;
     inTryStatement = true;
     node.visitChildren(this);
     inTryStatement = oldInTryStatement;
   }
 }