Fix a pretty bad bug of a class inheriting a patched class. The fix is

sdk/lib/_internal/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 "dart2jslib.dart";
 import "dart_types.dart";
 import "scanner/scannerlib.dart" show Token;
@@ skipping 327 matching lines @@
           Element boxElement = updatedElement.enclosingElement;
           assert(boxElement.kind == ElementKind.VARIABLE);
           boxes.add(boxElement);
         }
       });
       ClassElement closureElement = data.closureClassElement;
       assert(closureElement != null ||
              (fieldCaptures.isEmpty && boxes.isEmpty));
       void addElement(Element element, SourceString name) {
         Element fieldElement = new ClosureFieldElement(name, closureElement);
-        closureElement.addBackendMember(fieldElement);
+        closureElement.addMember(fieldElement, compiler);
         data.capturedFieldMapping[fieldElement] = element;
         freeVariableMapping[element] = fieldElement;
       }
       // Add the box elements first so we get the same ordering.
       // TODO(sra): What is the canonical order of multiple boxes?
       for (Element capturedElement in boxes) {
         addElement(capturedElement, capturedElement.name);
       }
       for (Element capturedElement in
                Elements.sortedByPosition(fieldCaptures)) {
@@ skipping 294 matching lines @@
   }
 
   ClosureClassMap globalizeClosure(FunctionExpression node, Element element) {
     SourceString closureName = new SourceString(computeClosureName(element));
     ClassElement globalizedElement = new ClosureClassElement(
         node, closureName, compiler, element, element.getCompilationUnit());
     FunctionElement callElement =
         new FunctionElementX.from(Compiler.CALL_OPERATOR_NAME,
                                   element,
                                   globalizedElement);
-    globalizedElement.addBackendMember(callElement);
+    globalizedElement.addMember(callElement, compiler);
     // The nested function's 'this' is the same as the one for the outer
     // function. It could be [null] if we are inside a static method.
     Element thisElement = closureData.thisElement;
     return new ClosureClassMap(element, globalizedElement,
                                callElement, thisElement);
   }
 
   void visitInvokable(Element element, Expression node, void visitChildren()) {
     bool oldInsideClosure = insideClosure;
     Element oldFunctionElement = currentElement;
@@ skipping 93 matching lines @@
   }
 
   visitTryStatement(TryStatement node) {
     // TODO(ngeoffray): implement finer grain state.
     bool oldInTryStatement = inTryStatement;
     inTryStatement = true;
     node.visitChildren(this);
     inTryStatement = oldInTryStatement;
   }
 }