Serialize NativeBehavior for elements

pkg/compiler/lib/src/js_backend/native_data.dart

 // Copyright (c) 2016, 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 js_backend.native_data;
 
 import '../common.dart';
 import '../elements/elements.dart'
     show ClassElement, Element, FieldElement, FunctionElement, MemberElement;
 import '../native/behavior.dart' show NativeBehavior;
 
 /// Additional element information for native classes and methods and js-interop
 /// methods.
 class NativeData {
   /// The JavaScript names for elements implemented via typed JavaScript
   /// interop.
   Map<Element, String> jsInteropNames = <Element, String>{};
 
   /// The JavaScript names for native JavaScript elements implemented.
   Map<Element, String> nativeMemberName = <Element, String>{};
 
   /// Tag info for native JavaScript classes names. See
   /// [setNativeClassTagInfo].
   Map<ClassElement, String> nativeClassTagInfo = <ClassElement, String>{};
 
-  // TODO(johnniwinther): Serialize these.
   /// Cache for [NativeBehavior]s for calling native methods.
   Map<FunctionElement, NativeBehavior> nativeMethodBehavior =
       <FunctionElement, NativeBehavior>{};
 
   /// Cache for [NativeBehavior]s for reading from native fields.
   Map<MemberElement, NativeBehavior> nativeFieldLoadBehavior =
       <FieldElement, NativeBehavior>{};
 
   /// Cache for [NativeBehavior]s for writing to native fields.
   Map<MemberElement, NativeBehavior> nativeFieldStoreBehavior =
@@ skipping 174 matching lines @@
   void setNativeFieldLoadBehavior(FieldElement field, NativeBehavior behavior) {
     nativeFieldLoadBehavior[field] = behavior;
   }
 
   /// Registers the [behavior] for writing to the native [field].
   void setNativeFieldStoreBehavior(
       FieldElement field, NativeBehavior behavior) {
     nativeFieldStoreBehavior[field] = behavior;
   }
 }