Implement complex super assignment.

sdk/lib/_internal/compiler/implementation/elements/modelx.dart

 // Copyright (c) 2013, 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.modelx;
 
 import 'dart:uri';
 import 'dart:collection' show LinkedHashMap;
 
 import 'elements.dart';
@@ skipping 1504 matching lines @@
    * Find the first member in the class chain with the given [selector].
    *
    * This method is NOT to be used for resolving
    * unqualified sends because it does not implement the scoping
    * rules, where library scope comes before superclass scope.
    *
    * When called on the implementation element both members declared in the
    * origin and the patch class are returned.
    */
   Element lookupSelector(Selector selector) {
+    return internalLookupSelector(selector, false);
+  }
+
+  Element lookupSuperSelector(Selector selector) {
+    return internalLookupSelector(selector, true);
+  }
+  
+  Element internalLookupSelector(Selector selector, bool isSuperLookup) {
     SourceString name = selector.name;
     bool isPrivate = name.isPrivate();
     LibraryElement library = selector.library;
-    for (ClassElement current = this;
+    for (ClassElement current = isSuperLookup ? superclass : this;
          current != null;
          current = current.superclass) {
       Element member = current.lookupLocalMember(name);
       if (member == null) continue;
       // Private members from a different library are not visible.
       if (isPrivate && !identical(library, member.getLibrary())) continue;
       // Static members are not inherited.
       if (member.modifiers.isStatic() && !identical(this, current)) continue;
       // If we find an abstract field we have to make sure that it has
       // the getter or setter part we're actually looking
@@ skipping 469 matching lines @@
 
   MetadataAnnotation ensureResolved(Compiler compiler) {
     if (resolutionState == STATE_NOT_STARTED) {
       compiler.resolver.resolveMetadataAnnotation(this);
     }
     return this;
   }
 
   String toString() => 'MetadataAnnotation($value, $resolutionState)';
 }