Address review comments.

frog/leg/namer.dart

 // Copyright (c) 2011, 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.
 
 /**
  * Assigns JavaScript identifiers to Dart variables, class-names and members.
  */
 class Namer {
   final Compiler compiler;
 
@@ skipping 43 matching lines @@
   }
 
   /**
    * Returns a preferred JS-id for the given top-level or static element.
    * The returned id is guaranteed to be a valid JS-id.
    */
   String _computeGuess(Element element) {
     assert(!element.isInstanceMember());
     if (element.kind == ElementKind.GENERATIVE_CONSTRUCTOR) {
       SourceString name = getConstructorName(element);
-      return instanceMethodName(name, element.parameterCount(compiler));
+      FunctionElement functionElement = element;
+      return instanceMethodName(name, functionElement.parameterCount(compiler));
     } else {
       // TODO(floitsch): deal with named constructors.
       String name = '${element.name}';
       if (element.kind == ElementKind.FUNCTION) {
         FunctionElement functionElement = element;
         name = '$name\$${functionElement.parameterCount(compiler)}';
       }
       // Prefix the name with '$' if it is reserved.
       if (jsReserved.contains(name)) {
         name = "\$$name";
@@ skipping 90 matching lines @@
   }
 
   String isolateBailoutAccess(Element element) {
     return '${isolateAccess(element)}\$bailout';
   }
 
   String operatorIs(ClassElement element) {
     return 'is\$${getName(element)}';
   }
 }