Use the typedef arity to know how to invoke a closure given by the dom.

dart/lib/compiler/implementation/compiler.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.
 
 class WorkItem {
   final Element element;
   TreeElements resolutionTree;
   bool allowSpeculativeOptimization = true;
   List<HTypeGuard> guards = const <HTypeGuard>[];
 
@@ skipping 422 matching lines @@
 
   Type resolveTypeAnnotation(Element element, TypeAnnotation annotation) {
     return resolver.resolveTypeAnnotation(element, annotation);
   }
 
   FunctionSignature resolveSignature(FunctionElement element) {
     return withCurrentElement(element,
                               () => resolver.resolveSignature(element));
   }
 
+  FunctionSignature resolveTypedef(TypedefElement element) {
+    return withCurrentElement(element,
+                              () => resolver.resolveTypedef(element));
+  }
+
+  FunctionType computeFunctionType(Element element,
+                                   FunctionSignature signature) {
+    return withCurrentElement(element,
+        () => resolver.computeFunctionType(element, signature));
+  }
+
   Constant compileVariable(VariableElement element) {
     return withCurrentElement(element, () {
       return constantHandler.compileVariable(element);
     });
   }
 
   reportWarning(Node node, var message) {
     if (message is TypeWarning) {
       // TODO(ahe): Don't supress these warning when the type checker
       // is more complete.
@@ skipping 130 matching lines @@
     // invariant that endOffset > beginOffset, but for EOF the
     // charoffset of the next token may be [beginOffset]. This can
     // also happen for synthetized tokens that are produced during
     // error handling.
     final endOffset =
       Math.max((end.next !== null) ? end.next.charOffset : 0, beginOffset + 1);
     assert(endOffset > beginOffset);
     return f(beginOffset, endOffset);
   }
 }