sync_unit_tests: add test for unknown field retention.

Retaining unknown fields is important for the sync protocol, so it's
good to test that it's working. In the future, when we hopefully have
a lite runtime with retention abilities, this test will make sure that
we haven't broken anything.

BUG=56579
TEST=sync_unit_tests

http://codereview.chromium.org/3384024

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@60701 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/sync/protocol/sync_proto.gyp

@@ -23,6 +23,7 @@
         'password_specifics.proto',
         'preference_specifics.proto',
         'session_specifics.proto',
+        'test.proto',
         'theme_specifics.proto',
         'typed_url_specifics.proto',
       ],

chrome/browser/sync/protocol/test.proto

@@ -0,0 +1,24 @@
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Protocol messages used only for testing.
+
+syntax = "proto2";
+
+// TODO(agl): In the future we hope that the lite runtime will be able to
+// handle unknown fields in messages. Until then, we use the full runtime.
+
+// option optimize_for = LITE_RUNTIME;
+// option retain_unknown_fields = true;
+
+package sync_pb;
+
+message UnknownFieldsTestA {
+  required bool foo = 1;
+}
+
+message UnknownFieldsTestB {
+  required bool foo = 1;
+  required bool bar = 2;
+}

chrome/browser/sync/util/protobuf_unittest.cc

@@ -0,0 +1,35 @@
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <string>
+#include <vector>
+
+#include "chrome/browser/sync/protocol/test.pb.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+TEST(SyncProtobufTest, TestUnknownFields) {
+  // This tests ensures that we retain unknown fields in protocol buffers by
+  // serialising UnknownFieldsTestB, which is a superset of UnknownFieldsTestA,
+  // and checking we get back to the same message after parsing/serialising via
+  // UnknownFieldsTestA.
+  sync_pb::UnknownFieldsTestA a;
+  sync_pb::UnknownFieldsTestB b;
+  sync_pb::UnknownFieldsTestB b2;
+
+  b.set_foo(true);
+  b.set_bar(true);
+  std::string serialized;
+  ASSERT_TRUE(b.SerializeToString(&serialized));
+  ASSERT_TRUE(a.ParseFromString(serialized));
+  ASSERT_TRUE(a.foo());
+  std::string serialized2;
+  ASSERT_TRUE(a.SerializeToString(&serialized2));
+  ASSERT_TRUE(b2.ParseFromString(serialized2));
+  ASSERT_TRUE(b2.foo());
+  ASSERT_TRUE(b2.bar());
+}
+
+}  // namespace

chrome/chrome_tests.gypi

@@ -2266,6 +2266,7 @@
       'target_name': 'sync_unit_tests',
       'type': 'executable',
       'sources': [
+        '<(protoc_out_dir)/chrome/browser/sync/protocol/test.pb.cc',
         'app/breakpad_mac_stubs.mm',
         'browser/sync/engine/apply_updates_command_unittest.cc',
         'browser/sync/engine/clear_data_command_unittest.cc',
@@ -2294,6 +2295,7 @@
         'browser/sync/util/crypto_helpers_unittest.cc',
         'browser/sync/util/data_encryption_unittest.cc',
         'browser/sync/util/extensions_activity_monitor_unittest.cc',
+        'browser/sync/util/protobuf_unittest.cc',
         'browser/sync/util/user_settings_unittest.cc',
         'test/file_test_utils.cc',
         'test/sync/engine/mock_connection_manager.cc',