Fix the order in which elements are emitted.

lib/compiler/implementation/dart_backend/emitter.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.
 
 /**
  * Dart backend helper for converting program IR back to source code.
  */
 class Emitter {
 
   final Compiler compiler;
   final Map<Node, String> renames;
+  final Map<ClassElement, Collection<Element>> classMembers;
   final StringBuffer sb;
   final Set<VariableListElement> processedVariableLists;
   Unparser unparser;
 
-  Emitter(this.compiler, this.renames) :
+  Emitter(this.compiler, this.renames, this.classMembers) :
       sb = new StringBuffer(),
       processedVariableLists = new Set<VariableListElement>() {
     unparser = new Unparser.withRenamer((Node node) => renames[node]);
   }
 
   /**
    * Outputs given class element with selected inner elements.
    */
-  void outputClass(ClassElement classElement, Set<Element> innerElements) {
+  void outputClass(ClassElement classElement, Collection<Element> members) {
     ClassNode classNode = classElement.parseNode(compiler);
     // classElement.beginToken is 'class', 'interface', or 'abstract'.
     sb.add(classNode.beginToken.slowToString());
     if (classNode.beginToken.slowToString() == 'abstract') {
       sb.add(' ');
       sb.add(classNode.beginToken.next.slowToString());  // 'class'
     }
     sb.add(' ');
     sb.add(unparser.unparse(classNode.name));
     if (classNode.typeParameters !== null) {
       sb.add(unparser.unparse(classNode.typeParameters));
     }
     if (classNode.extendsKeyword !== null) {
       sb.add(' ');
       classNode.extendsKeyword.value.printOn(sb);
       sb.add(' ');
       sb.add(unparser.unparse(classNode.superclass));
     }
     if (!classNode.interfaces.isEmpty()) {
       sb.add(' ');
       sb.add(unparser.unparse(classNode.interfaces));
     }
     if (classNode.defaultClause !== null) {
       sb.add(' default ');
       sb.add(unparser.unparse(classNode.defaultClause));
     }
     sb.add('{');
-    innerElements.forEach((element) {
+    members.forEach((element) {
       // TODO(smok): Filter out default constructors here.
       outputElement(element);
     });
     sb.add('}');
   }
 
   void outputElement(Element element) {
+    if (element is ClassElement) {
+      outputClass(element, classMembers[element]);
+      return;
+    }
+
     // TODO(smok): Figure out why AbstractFieldElement appears here,
     // we have used getters/setters resolved instead of it.
     if (element is SynthesizedConstructorElement
         || element is AbstractFieldElement) return;
     if (element.isField()) {
       assert(element is VariableElement);
       // Different VariableElement's may refer to the same VariableListElement.
       // Output this list only once.
       // TODO: only emit used variables.
       VariableElement variableElement = element;
@@ skipping 16 matching lines @@
       if (!uri.startsWith('dart:')) continue;
       final lib = libraries[uri];
       if (imports.containsKey(lib)) {
         sb.add('#import("$uri", prefix: "${imports[lib]}");');
       }
     }
   }
 
   String toString() => sb.toString();
 }