[Sync] Reimplement proto value conversions on top of field visitors.

components/sync/protocol/proto_visitors.h

Index: components/sync/protocol/proto_visitors.h
diff --git a/components/sync/protocol/proto_visitors.h b/components/sync/protocol/proto_visitors.h
new file mode 100644
index 0000000000000000000000000000000000000000..8027b62ac06a5fff95ae87aabecc69c127406169
--- /dev/null
+++ b/components/sync/protocol/proto_visitors.h
@@ -0,0 +1,944 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.

[pavely, 2016/10/20 05:10:39]

You need to add this file to BUILD.gn too.

[Dmitry Skiba, 2016/10/20 18:31:19]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_SYNC_PROTOCOL_PROTO_VISITORS_H_
+#define COMPONENTS_SYNC_PROTOCOL_PROTO_VISITORS_H_
+
+#include "components/sync/protocol/app_list_specifics.pb.h"
+#include "components/sync/protocol/app_notification_specifics.pb.h"
+#include "components/sync/protocol/app_setting_specifics.pb.h"
+#include "components/sync/protocol/app_specifics.pb.h"
+#include "components/sync/protocol/arc_package_specifics.pb.h"
+#include "components/sync/protocol/autofill_specifics.pb.h"
+#include "components/sync/protocol/bookmark_specifics.pb.h"
+#include "components/sync/protocol/dictionary_specifics.pb.h"
+#include "components/sync/protocol/encryption.pb.h"
+#include "components/sync/protocol/entity_metadata.pb.h"
+#include "components/sync/protocol/experiments_specifics.pb.h"
+#include "components/sync/protocol/extension_setting_specifics.pb.h"
+#include "components/sync/protocol/extension_specifics.pb.h"
+#include "components/sync/protocol/favicon_image_specifics.pb.h"
+#include "components/sync/protocol/favicon_tracking_specifics.pb.h"
+#include "components/sync/protocol/history_delete_directive_specifics.pb.h"
+#include "components/sync/protocol/nigori_specifics.pb.h"
+#include "components/sync/protocol/password_specifics.pb.h"
+#include "components/sync/protocol/preference_specifics.pb.h"
+#include "components/sync/protocol/printer_specifics.pb.h"
+#include "components/sync/protocol/priority_preference_specifics.pb.h"
+#include "components/sync/protocol/proto_enum_conversions.h"
+#include "components/sync/protocol/reading_list_specifics.pb.h"
+#include "components/sync/protocol/search_engine_specifics.pb.h"
+#include "components/sync/protocol/session_specifics.pb.h"
+#include "components/sync/protocol/sync.pb.h"
+#include "components/sync/protocol/theme_specifics.pb.h"
+#include "components/sync/protocol/typed_url_specifics.pb.h"
+#include "components/sync/protocol/unique_position.pb.h"
+
+// This file implements VisitProtoFields() functions for sync protos.
+//
+// VisitProtoFields(visitor, proto) calls |visitor| for each field in
+// |proto|. When called, |visitor| gets passed |proto|, field name and
+// field value.
+//
+// VisitProtoFields() used to implement two distinctive features:
+// 1. Serialization into base::DictionaryValue
+// 2. Proto memory usage estimation
+//
+// To achieve that it's very important for VisitProtoFields() to be free
+// of any logic. It must just call visitor for each field in a proto.
+//
+// Logic (like clobbering sensitive fields) must be implemented in visitors.
+// For example see how ToValueVisitor (from proto_value_conversions.cc)
+// implements various customizations.
+
+#define VISIT_(Kind, field) \
+  if (proto.has_##field()) \
+    visitor.Visit##Kind(proto, #field, proto.field())
+
+// Generic version, calls visitor.Visit(). Handles almost everything except
+// for special cases below.
+#define VISIT(field) VISIT_(, field)
+
+// 'bytes' protobuf type maps to std::string, and is indistinguishable
+// from 'string' type. To solve that 'bytes' fields are special cased to
+// call visitor.VisitBytes().
+#define VISIT_BYTES(field) VISIT_(Bytes, field)
+
+// We could use template magic (std::is_enum) to handle enums, but that would
+// complicate visitors, and besides we already have special case for 'bytes',
+// so just add one more special case. Calls visitor.VisitEnum().
+#define VISIT_ENUM(field) VISIT_(Enum, field)
+
+// Repeated fields are always present, so there are no 'has_<field>' methods.
+// This macro unconditionally calls visitor.Visit().
+#define VISIT_REP(field) \
+  visitor.Visit(proto, #field, proto.field());
+
+namespace syncer {
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::EncryptedData& proto) {
+  VISIT(key_name);
+  // TODO(akalin): Shouldn't blob be of type bytes instead of string?
+  VISIT_BYTES(blob);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::PasswordSpecificsMetadata& proto) {
+  VISIT(url);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::AppNotificationSettings& proto) {
+  VISIT(initial_setup_done);
+  VISIT(disabled);
+  VISIT(oauth_client_id);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::SessionHeader& proto) {
+  VISIT_REP(window);
+  VISIT(client_name);
+  VISIT_ENUM(device_type);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::SessionTab& proto) {
+  VISIT(tab_id);
+  VISIT(window_id);
+  VISIT(tab_visual_index);
+  VISIT(current_navigation_index);
+  VISIT(pinned);
+  VISIT(extension_app_id);
+  VISIT_REP(navigation);
+  VISIT_BYTES(favicon);
+  VISIT_ENUM(favicon_type);
+  VISIT(favicon_source);
+  VISIT_REP(variation_id);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::SessionWindow& proto) {
+  VISIT(window_id);
+  VISIT(selected_tab_index);
+  VISIT_REP(tab);
+  VISIT_ENUM(browser_type);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::TabNavigation& proto) {
+  VISIT(virtual_url);
+  VISIT(referrer);
+  VISIT(title);
+  VISIT_ENUM(page_transition);
+  VISIT_ENUM(redirect_type);
+  VISIT(unique_id);
+  VISIT(timestamp_msec);
+  VISIT(navigation_forward_back);
+  VISIT(navigation_from_address_bar);
+  VISIT(navigation_home_page);
+  VISIT(navigation_chain_start);
+  VISIT(navigation_chain_end);
+  VISIT(global_id);
+  VISIT(search_terms);
+  VISIT(favicon_url);
+  VISIT_ENUM(blocked_state);
+  VISIT_REP(content_pack_categories);
+  VISIT(http_status_code);
+  VISIT(obsolete_referrer_policy);
+  VISIT(is_restored);
+  VISIT_REP(navigation_redirect);
+  VISIT(last_navigation_redirect_url);
+  VISIT(correct_referrer_policy);
+  VISIT_ENUM(password_state);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::NavigationRedirect& proto) {
+  VISIT(url);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::PasswordSpecificsData& proto) {
+  VISIT(scheme);
+  VISIT(signon_realm);
+  VISIT(origin);
+  VISIT(action);
+  VISIT(username_element);
+  VISIT(username_value);
+  VISIT(password_element);
+  VISIT(preferred);
+  VISIT(date_created);
+  VISIT(blacklisted);
+  VISIT(type);
+  VISIT(times_used);
+  VISIT(display_name);
+  VISIT(avatar_url);
+  VISIT(federation_url);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::GlobalIdDirective& proto) {
+  VISIT_REP(global_id);
+  VISIT(start_time_usec);
+  VISIT(end_time_usec);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::TimeRangeDirective& proto) {
+  VISIT(start_time_usec);
+  VISIT(end_time_usec);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::AppListSpecifics& proto) {
+  VISIT(item_id);
+  VISIT_ENUM(item_type);
+  VISIT(item_name);
+  VISIT(parent_id);
+  VISIT(item_ordinal);
+  VISIT(item_pin_ordinal);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::ArcPackageSpecifics& proto) {
+  VISIT(package_name);
+  VISIT(package_version);
+  VISIT(last_backup_android_id);
+  VISIT(last_backup_time);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::PrinterPPDData& proto) {
+  VISIT(id);
+  VISIT(file_name);
+  VISIT(version_number);
+  VISIT(from_quirks_server);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::ReadingListSpecifics& proto) {
+  VISIT(entry_id);
+  VISIT(title);
+  VISIT(url);
+  VISIT(creation_time_us);
+  VISIT(update_time_us);
+  VISIT_ENUM(status);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::AppNotification& proto) {
+  VISIT(guid);
+  VISIT(app_id);
+  VISIT(creation_timestamp_ms);
+  VISIT(title);
+  VISIT(body_text);
+  VISIT(link_url);
+  VISIT(link_text);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::AppSettingSpecifics& proto) {
+  VISIT(extension_setting);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::LinkedAppIconInfo& proto) {
+  VISIT(url);
+  VISIT(size);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::AppSpecifics& proto) {
+  VISIT(extension);
+  VISIT(notification_settings);
+  VISIT(app_launch_ordinal);
+  VISIT(page_ordinal);
+  VISIT_ENUM(launch_type);
+  VISIT(bookmark_app_url);
+  VISIT(bookmark_app_description);
+  VISIT(bookmark_app_icon_color);
+  VISIT_REP(linked_app_icons);
+
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::AutofillSpecifics& proto) {
+  VISIT(name);
+  VISIT(value);
+  VISIT_REP(usage_timestamp);
+  VISIT(profile);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::AutofillProfileSpecifics& proto) {
+  VISIT(guid);
+  VISIT(origin);
+  VISIT(use_count);
+  VISIT(use_date);
+  VISIT_REP(name_first);
+  VISIT_REP(name_middle);
+  VISIT_REP(name_last);
+  VISIT_REP(name_full);
+  VISIT_REP(email_address);
+  VISIT(company_name);
+  VISIT(address_home_line1);
+  VISIT(address_home_line2);
+  VISIT(address_home_city);
+  VISIT(address_home_state);
+  VISIT(address_home_zip);
+  VISIT(address_home_country);
+  VISIT(address_home_street_address);
+  VISIT(address_home_sorting_code);
+  VISIT(address_home_dependent_locality);
+  VISIT(address_home_language_code);
+  VISIT_REP(phone_home_whole_number);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::WalletMetadataSpecifics& proto) {
+  VISIT_ENUM(type);
+  VISIT(id);
+  VISIT(use_count);
+  VISIT(use_date);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::AutofillWalletSpecifics& proto) {
+  VISIT_ENUM(type);
+  VISIT(masked_card);
+  VISIT(address);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::MetaInfo& proto) {
+  VISIT(key);
+  VISIT(value);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::BookmarkSpecifics& proto) {
+  VISIT(url);
+  VISIT_BYTES(favicon);
+  VISIT(title);
+  VISIT(creation_time_us);
+  VISIT(icon_url);
+  VISIT_REP(meta_info);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::DeviceInfoSpecifics& proto) {
+  VISIT(cache_guid);
+  VISIT(client_name);
+  VISIT_ENUM(device_type);
+  VISIT(sync_user_agent);
+  VISIT(chrome_version);
+  VISIT(signin_scoped_device_id);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::DictionarySpecifics& proto) {
+  VISIT(word);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::FaviconSyncFlags& proto) {
+  VISIT(enabled);
+  VISIT(favicon_sync_limit);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::KeystoreEncryptionFlags& proto) {
+  VISIT(enabled);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::HistoryDeleteDirectives& proto) {
+  VISIT(enabled);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::AutofillCullingFlags& proto) {
+  VISIT(enabled);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::PreCommitUpdateAvoidanceFlags& proto) {
+  VISIT(enabled);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::GcmChannelFlags& proto) {
+  VISIT(enabled);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::GcmInvalidationsFlags& proto) {
+  VISIT(enabled);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::ExperimentsSpecifics& proto) {
+  VISIT(keystore_encryption);
+  VISIT(history_delete_directives);
+  VISIT(autofill_culling);
+  VISIT(pre_commit_update_avoidance);
+  VISIT(favicon_sync);
+  VISIT(gcm_channel);
+  VISIT(gcm_invalidations);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::ExtensionSettingSpecifics& proto) {
+  VISIT(extension_id);
+  VISIT(key);
+  VISIT(value);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::ExtensionSpecifics& proto) {
+  VISIT(id);
+  VISIT(version);
+  VISIT(update_url);
+  VISIT(enabled);
+  VISIT(incognito_enabled);
+  VISIT(name);
+  VISIT(remote_install);
+  VISIT(installed_by_custodian);
+  VISIT(all_urls_enabled);
+  VISIT(disable_reasons);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::FaviconData& proto) {
+  VISIT_BYTES(favicon);
+  VISIT(width);
+  VISIT(height);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::FaviconImageSpecifics& proto) {
+  VISIT(favicon_url);
+  VISIT(favicon_web);
+  VISIT(favicon_web_32);
+  VISIT(favicon_touch_64);
+  VISIT(favicon_touch_precomposed_64);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::FaviconTrackingSpecifics& proto) {
+  VISIT(favicon_url);
+  VISIT(last_visit_time_ms);
+  VISIT(is_bookmarked);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::HistoryDeleteDirectiveSpecifics& proto) {
+  VISIT(global_id_directive);
+  VISIT(time_range_directive);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::ManagedUserSettingSpecifics& proto) {
+  VISIT(name);
+  VISIT(value);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::ManagedUserSpecifics& proto) {
+  VISIT(id);
+  VISIT(name);
+  VISIT(acknowledged);
+  VISIT(master_key);
+  VISIT(chrome_avatar);
+  VISIT(chromeos_avatar);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::ManagedUserSharedSettingSpecifics& proto) {
+  VISIT(mu_id);
+  VISIT(key);
+  VISIT(value);
+  VISIT(acknowledged);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::ManagedUserWhitelistSpecifics& proto) {
+  VISIT(id);
+  VISIT(name);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::NigoriSpecifics& proto) {
+  VISIT(encryption_keybag);
+  VISIT(keybag_is_frozen);
+  VISIT(encrypt_bookmarks);
+  VISIT(encrypt_preferences);
+  VISIT(encrypt_autofill_profile);
+  VISIT(encrypt_autofill);
+  VISIT(encrypt_themes);
+  VISIT(encrypt_typed_urls);
+  VISIT(encrypt_extension_settings);
+  VISIT(encrypt_extensions);
+  VISIT(encrypt_sessions);
+  VISIT(encrypt_app_settings);
+  VISIT(encrypt_apps);
+  VISIT(encrypt_search_engines);
+  VISIT(encrypt_dictionary);
+  VISIT(encrypt_articles);
+  VISIT(encrypt_app_list);
+  VISIT(encrypt_arc_package);
+  VISIT(encrypt_reading_list);
+  VISIT(encrypt_everything);
+  VISIT(server_only_was_missing_keystore_migration_time);
+  VISIT(sync_tab_favicons);
+  VISIT_ENUM(passphrase_type);
+  VISIT(keystore_decryptor_token);
+  VISIT(keystore_migration_time);
+  VISIT(custom_passphrase_time);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::ArticlePage& proto) {
+  VISIT(url);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::ArticleSpecifics& proto) {
+  VISIT(entry_id);
+  VISIT(title);
+  VISIT_REP(pages);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::PasswordSpecifics& proto) {
+  VISIT(encrypted);
+  VISIT(unencrypted_metadata);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::PreferenceSpecifics& proto) {
+  VISIT(name);
+  VISIT(value);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::PrinterSpecifics& proto) {
+  VISIT(id);
+  VISIT(display_name);
+  VISIT(description);
+  VISIT(manufacturer);
+  VISIT(model);
+  VISIT(uri);
+  VISIT(uuid);
+  VISIT(ppd);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::PriorityPreferenceSpecifics& proto) {
+  VISIT(preference);
+}
+
+template <class V>
+void VisitProtoFields(
+    V& visitor,
+    const sync_pb::SyncedNotificationAppInfoSpecifics& proto) {
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::SyncedNotificationSpecifics& proto) {
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::SearchEngineSpecifics& proto) {
+  VISIT(short_name);
+  VISIT(keyword);
+  VISIT(favicon_url);
+  VISIT(url);
+  VISIT(safe_for_autoreplace);
+  VISIT(originating_url);
+  VISIT(date_created);
+  VISIT(input_encodings);
+  VISIT(show_in_default_list);
+  VISIT(suggestions_url);
+  VISIT(prepopulate_id);
+  VISIT(autogenerate_keyword);
+  VISIT(instant_url);
+  VISIT(last_modified);
+  VISIT(sync_guid);
+  VISIT_REP(alternate_urls);
+  VISIT(search_terms_replacement_key);
+  VISIT(image_url);
+  VISIT(search_url_post_params);
+  VISIT(suggestions_url_post_params);
+  VISIT(instant_url_post_params);
+  VISIT(image_url_post_params);
+  VISIT(new_tab_url);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::SessionSpecifics& proto) {
+  VISIT(session_tag);
+  VISIT(header);
+  VISIT(tab);
+  VISIT(tab_node_id);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::ThemeSpecifics& proto) {
+  VISIT(use_custom_theme);
+  VISIT(use_system_theme_by_default);
+  VISIT(custom_theme_name);
+  VISIT(custom_theme_id);
+  VISIT(custom_theme_update_url);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::TypedUrlSpecifics& proto) {
+  VISIT(url);
+  VISIT(title);
+  VISIT(hidden);
+  VISIT_REP(visits);
+  VISIT_REP(visit_transitions);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::WalletMaskedCreditCard& proto) {
+  VISIT(id);
+  VISIT_ENUM(status);
+  VISIT(name_on_card);
+  VISIT_ENUM(type);
+  VISIT(last_four);
+  VISIT(exp_month);
+  VISIT(exp_year);
+  VISIT(billing_address_id);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::WalletPostalAddress& proto) {
+  VISIT(id);
+  VISIT(recipient_name);
+  VISIT(company_name);
+  VISIT_REP(street_address);
+  VISIT(address_1);
+  VISIT(address_2);
+  VISIT(address_3);
+  VISIT(address_4);
+  VISIT(postal_code);
+  VISIT(sorting_code);
+  VISIT(country_code);
+  VISIT(phone_number);
+  VISIT(language_code);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::WifiCredentialSpecifics& proto) {
+  VISIT_BYTES(ssid);
+  VISIT_ENUM(security_class);
+  VISIT_BYTES(passphrase);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::EntitySpecifics& proto) {
+  VISIT(app);
+  VISIT(app_list);
+  VISIT(app_notification);
+  VISIT(app_setting);
+  VISIT(arc_package);
+  VISIT(article);
+  VISIT(autofill);
+  VISIT(autofill_profile);
+  VISIT(autofill_wallet);
+  VISIT(wallet_metadata);
+  VISIT(bookmark);
+  VISIT(device_info);
+  VISIT(dictionary);
+  VISIT(experiments);
+  VISIT(extension);
+  VISIT(extension_setting);
+  VISIT(favicon_image);
+  VISIT(favicon_tracking);
+  VISIT(history_delete_directive);
+  VISIT(managed_user_setting);
+  VISIT(managed_user_shared_setting);
+  VISIT(managed_user);
+  VISIT(managed_user_whitelist);
+  VISIT(nigori);
+  VISIT(password);
+  VISIT(preference);
+  VISIT(printer);
+  VISIT(priority_preference);
+  VISIT(reading_list);
+  VISIT(search_engine);
+  VISIT(session);
+  VISIT(synced_notification);
+  VISIT(synced_notification_app_info);
+  VISIT(theme);
+  VISIT(typed_url);
+  VISIT(wifi_credential);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::SyncEntity& proto) {
+  VISIT(id_string);
+  VISIT(parent_id_string);
+  VISIT(old_parent_id);
+  VISIT(version);
+  VISIT(mtime);
+  VISIT(ctime);
+  VISIT(name);
+  VISIT(non_unique_name);
+  VISIT(sync_timestamp);
+  VISIT(server_defined_unique_tag);
+  VISIT(position_in_parent);
+  VISIT(unique_position);
+  VISIT(insert_after_item_id);
+  VISIT(deleted);
+  VISIT(originator_cache_guid);
+  VISIT(originator_client_item_id);
+  VISIT(specifics);
+  VISIT(folder);
+  VISIT(client_defined_unique_tag);
+  VISIT_REP(attachment_id);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::ChromiumExtensionsActivity& proto) {
+  VISIT(extension_id);
+  VISIT(bookmark_writes_since_last_commit);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::CommitMessage& proto) {
+  VISIT_REP(entries);
+  VISIT(cache_guid);
+  VISIT_REP(extensions_activity);
+  VISIT(config_params);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::GetUpdateTriggers& proto) {
+  VISIT_REP(notification_hint);
+  VISIT(client_dropped_hints);
+  VISIT(invalidations_out_of_sync);
+  VISIT(local_modification_nudges);
+  VISIT(datatype_refresh_nudges);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::DataTypeProgressMarker& proto) {
+  VISIT(data_type_id);
+  VISIT_BYTES(token);
+  VISIT(timestamp_token_for_migration);
+  VISIT(notification_hint);
+  VISIT(get_update_triggers);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::DataTypeContext& proto) {
+  VISIT(data_type_id);
+  VISIT(context);
+  VISIT(version);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::GetUpdatesCallerInfo& proto) {
+  VISIT_ENUM(source);
+  VISIT(notifications_enabled);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::GetUpdatesMessage& proto) {
+  VISIT(caller_info);
+  VISIT(fetch_folders);
+  VISIT(batch_size);
+  VISIT_REP(from_progress_marker);
+  VISIT(streaming);
+  VISIT(need_encryption_key);
+  VISIT(create_mobile_bookmarks_folder);
+  VISIT_ENUM(get_updates_origin);
+  VISIT_REP(client_contexts);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::ClientStatus& proto) {
+  VISIT(hierarchy_conflict_detected);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::CommitResponse::EntryResponse& proto) {
+  VISIT_ENUM(response_type);
+  VISIT(id_string);
+  VISIT(parent_id_string);
+  VISIT(position_in_parent);
+  VISIT(version);
+  VISIT(name);
+  VISIT(error_message);
+  VISIT(mtime);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::CommitResponse& proto) {
+  VISIT_REP(entryresponse);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::GetUpdatesResponse& proto) {
+  VISIT_REP(entries)
+  VISIT(changes_remaining);
+  VISIT_REP(new_progress_marker);
+  VISIT_REP(context_mutations);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::ClientCommand& proto) {
+  VISIT(set_sync_poll_interval);
+  VISIT(set_sync_long_poll_interval);
+  VISIT(max_commit_batch_size);
+  VISIT(sessions_commit_delay_seconds);
+  VISIT(throttle_delay_seconds);
+  VISIT(client_invalidation_hint_buffer_size);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::ClientToServerResponse::Error& proto) {
+  VISIT_ENUM(error_type);
+  VISIT(error_description);
+  VISIT(url);
+  VISIT_ENUM(action);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::ClientToServerResponse& proto) {
+  VISIT(commit);
+  VISIT(get_updates);
+  VISIT(error);
+  VISIT_ENUM(error_code);
+  VISIT(error_message);
+  VISIT(store_birthday);
+  VISIT(client_command);
+  VISIT_REP(migrated_data_type_id);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::ClientToServerMessage& proto) {
+  VISIT(share);
+  VISIT(protocol_version);
+  VISIT(commit);
+  VISIT(get_updates);
+  VISIT(store_birthday);
+  VISIT(sync_problem_detected);
+  VISIT(debug_info);
+  VISIT(client_status);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::DatatypeAssociationStats& proto) {
+  VISIT(data_type_id);
+  VISIT(num_local_items_before_association);
+  VISIT(num_sync_items_before_association);
+  VISIT(num_local_items_after_association);
+  VISIT(num_sync_items_after_association);
+  VISIT(num_local_items_added);
+  VISIT(num_local_items_deleted);
+  VISIT(num_local_items_modified);
+  VISIT(num_sync_items_added);
+  VISIT(num_sync_items_deleted);
+  VISIT(num_sync_items_modified);
+  VISIT(local_version_pre_association);
+  VISIT(sync_version_pre_association);
+  VISIT(had_error);
+  VISIT(download_wait_time_us);
+  VISIT(download_time_us);
+  VISIT(association_wait_time_for_high_priority_us);
+  VISIT(association_wait_time_for_same_priority_us);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::DebugEventInfo& proto) {
+  VISIT_ENUM(singleton_event);
+  VISIT(sync_cycle_completed_event_info);
+  VISIT(nudging_datatype);
+  VISIT_REP(datatypes_notified_from_server);
+  VISIT(datatype_association_stats);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::DebugInfo& proto) {
+  VISIT_REP(events);
+  VISIT(cryptographer_ready);
+  VISIT(cryptographer_has_pending_keys);
+  VISIT(events_dropped);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor,
+                      const sync_pb::SyncCycleCompletedEventInfo& proto) {
+  VISIT(num_encryption_conflicts);
+  VISIT(num_hierarchy_conflicts);
+  VISIT(num_server_conflicts);
+  VISIT(num_updates_downloaded);
+  VISIT(num_reflected_updates_downloaded);
+  VISIT(caller_info);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::ClientConfigParams& proto) {
+  VISIT_REP(enabled_type_ids);
+  VISIT(tabs_datatype_enabled);
+  VISIT(cookie_jar_mismatch);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::AttachmentIdProto& proto) {
+  VISIT(unique_id);
+}
+
+template <class V>
+void VisitProtoFields(V& visitor, const sync_pb::EntityMetadata& proto) {
+  VISIT(client_tag_hash);
+  VISIT(server_id);
+  VISIT(is_deleted);
+  VISIT(sequence_number);
+  VISIT(acked_sequence_number);
+  VISIT(server_version);
+  VISIT(creation_time);
+  VISIT(modification_time);
+  VISIT(specifics_hash);
+  VISIT(base_specifics_hash);
+}
+
+}  // namespace syncer
+
+#undef VISIT_
+#undef VISIT_BYTES
+#undef VISIT_ENUM
+#undef VISIT
+#undef VISIT_REP
+
+#endif  // COMPONENTS_SYNC_PROTOCOL_PROTO_VISITORS_H_