Fix issues with protobuf equality comparisons

test/json_test.dart

 // Basic smoke tests for the GeneratedMessage JSON API.
 //
 // There are more JSON tests in the dart-protoc-plugin package.
 library json_test;
 
 import 'dart:convert';
 import 'package:test/test.dart';
 
-import 'mock_util.dart' show MockMessage;
+import 'mock_util.dart' show MockMessage, mockInfo;
 
 class T extends MockMessage {
-  get className => "T";
-  T create() => new T();
+  get info_ => _info;
+  static final _info = mockInfo("T", () => new T());
 }
 
 main() {
   T example = new T()
     ..val = 123
     ..str = "hello";
 
   test('testWriteToJson', () {
     String json = example.writeToJson();
     checkJsonMap(JSON.decode(json));
@@ skipping 20 matching lines @@
 checkJsonMap(Map m) {
   expect(m.length, 2);
   expect(m["1"], 123);
   expect(m["2"], "hello");
 }
 
 checkMessage(T t) {
   expect(t.val, 123);
   expect(t.str, "hello");
 }