Support instance methods in analyzer2dart.

pkg/analyzer2dart/lib/src/dart_backend.dart

 // Copyright (c) 2014, 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 analyzer2dart.dart_backend;
 
 import 'package:compiler/src/elements/elements.dart';
 import 'package:compiler/src/dart_backend/dart_backend.dart';
 import 'package:compiler/src/dart2jslib.dart';
 import 'package:compiler/src/dart_types.dart';
@@ skipping 10 matching lines @@
     libraries: convertedWorld.libraries,
     instantiatedClasses: convertedWorld.instantiatedClasses,
     resolvedElements: convertedWorld.resolvedElements,
     mainFunction: convertedWorld.mainFunction,
     computeElementAst: (Element element) {
       return DartBackend.createElementAst(
           context,
           element,
           convertedWorld.getIr(element));
     },
-    shouldOutput: (_) => true,
+    shouldOutput: (Element element) => !element.isSynthesized,
     isSafeToRemoveTypeDeclarations: (_) => false);
 }
 
 class _ElementAstCreationContext implements ElementAstCreationContext {
   final Listener listener;
 
   @override
   final DartTypes dartTypes;
 
   _ElementAstCreationContext(this.listener, this.dartTypes);
@@ skipping 58 matching lines @@
   @override
   spanFromSpannable(Spannable node) {
     // TODO: implement spanFromSpannable
   }
 
   @override
   withCurrentElement(element, f()) {
     // TODO: implement withCurrentElement
   }
 }