Make sure a class is resolved before looking up its elements.

frog/leg/elements/elements.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.
 
 #library('elements');
 
 #import('../tree/tree.dart');
 #import('../scanner/scannerlib.dart');
 #import('../leg.dart');  // TODO(karlklose): we only need type.
 #import('../util/util.dart');
@@ skipping 242 matching lines @@
     members = members.prepend(element);
   }
 
   Type computeType(compiler, types) {
     if (type === null) {
       type = new SimpleType(name, this);
     }
     return type;
   }
 
-  void resolve(Compiler compiler) {
-    if (isResolved) return;
-    compiler.resolveType(this);
-    isResolved = true;
+  ClassElement resolve(Compiler compiler) {
+    if (!isResolved) {
+      compiler.resolveType(this);
+      isResolved = true;
+    }
+    return this;
   }
 
   Element lookupLocalElement(SourceString name) {
     // TODO(karlklose): replace with more efficient solution.
     for (Link<Element> link = members;
          link !== null && !link.isEmpty();
          link = link.tail) {
       if (link.head.name == name) return link.head;
     }
     return null;
@@ skipping 34 matching lines @@
            && !element.isInstanceMember()
            && (element.kind === ElementKind.FIELD);
   }
 
   static bool isInstanceMethod(Element element) {
     return (element != null)
            && element.isInstanceMember()
            && (element.kind === ElementKind.FUNCTION);
   }
 }