Introduce IOSChromeSyncClient (upstream)

This is the upstream part of the downstream CL 307417013.

BUG=544795, 548612, 453435

Review URL: https://codereview.chromium.org/1471073006

Cr-Commit-Position: refs/heads/master@{#361976}

7 files changed, 500 insertions, 1 deletions

diff --git a/ios/chrome/browser/BUILD.gn b/ios/chrome/browser/BUILD.gn
index d1eb8e3..c8aed00 100644
--- a/ios/chrome/browser/BUILD.gn
+++ b/ios/chrome/browser/BUILD.gn
@@ -307,6 +307,8 @@ source_set("browser") {
     "suggestions/suggestions_service_factory.mm",
     "sync/glue/sync_start_util.cc",
     "sync/glue/sync_start_util.h",
+    "sync/ios_chrome_sync_client.cc",
+    "sync/ios_chrome_sync_client.h",
     "sync/ios_chrome_synced_tab_delegate.cc",
     "sync/ios_chrome_synced_tab_delegate.h",
     "sync/sessions/ios_chrome_local_session_event_router.cc",
@@ -440,6 +442,8 @@ source_set("browser") {
     "//components/autofill/ios/browser",
     "//components/bookmarks/browser",
     "//components/bookmarks/managed",
+    "//components/browser_sync/browser",
+    "//components/browser_sync/common",
     "//components/component_updater",
     "//components/content_settings/core/browser",
     "//components/crash/core/browser",
diff --git a/ios/chrome/browser/DEPS b/ios/chrome/browser/DEPS
index 99cebf3..b7084d0 100644
--- a/ios/chrome/browser/DEPS
+++ b/ios/chrome/browser/DEPS
@@ -5,6 +5,8 @@ include_rules = [
   "+components/autofill/core/common",
   "+components/autofill/ios/browser",
   "+components/bookmarks",
+  "+components/browser_sync/browser",
+  "+components/browser_sync/common",
   "+components/component_updater",
   "+components/content_settings/core",
   "+components/crash/core/browser",
diff --git a/ios/chrome/browser/sync/ios_chrome_sync_client.cc b/ios/chrome/browser/sync/ios_chrome_sync_client.cc
new file mode 100644
index 0000000..27e4cf0
--- /dev/null
+++ b/ios/chrome/browser/sync/ios_chrome_sync_client.cc
@@ -0,0 +1,392 @@
+// Copyright 2015 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 "ios/chrome/browser/sync/ios_chrome_sync_client.h"
+
+#include "base/bind.h"
+#include "base/command_line.h"
+#include "components/autofill/core/browser/webdata/autocomplete_syncable_service.h"
+#include "components/autofill/core/browser/webdata/autofill_profile_syncable_service.h"
+#include "components/autofill/core/browser/webdata/autofill_wallet_metadata_syncable_service.h"
+#include "components/autofill/core/browser/webdata/autofill_wallet_syncable_service.h"
+#include "components/autofill/core/browser/webdata/autofill_webdata_service.h"
+#include "components/browser_sync/browser/profile_sync_components_factory_impl.h"
+#include "components/browser_sync/browser/profile_sync_service.h"
+#include "components/browser_sync/common/browser_sync_switches.h"
+#include "components/dom_distiller/core/dom_distiller_service.h"
+#include "components/history/core/browser/history_model_worker.h"
+#include "components/history/core/browser/history_service.h"
+#include "components/invalidation/impl/profile_invalidation_provider.h"
+#include "components/keyed_service/core/service_access_type.h"
+#include "components/password_manager/core/browser/password_store.h"
+#include "components/password_manager/sync/browser/password_model_worker.h"
+#include "components/search_engines/search_engine_data_type_controller.h"
+#include "components/signin/core/browser/profile_oauth2_token_service.h"
+#include "components/sync_driver/glue/browser_thread_model_worker.h"
+#include "components/sync_driver/glue/chrome_report_unrecoverable_error.h"
+#include "components/sync_driver/glue/ui_model_worker.h"
+#include "components/sync_driver/sync_api_component_factory.h"
+#include "components/sync_driver/sync_util.h"
+#include "components/sync_driver/ui_data_type_controller.h"
+#include "components/sync_sessions/favicon_cache.h"
+#include "components/sync_sessions/local_session_event_router.h"
+#include "components/sync_sessions/sync_sessions_client.h"
+#include "components/sync_sessions/synced_window_delegates_getter.h"
+#include "components/syncable_prefs/pref_service_syncable.h"
+#include "ios/chrome/browser/autofill/personal_data_manager_factory.h"
+#include "ios/chrome/browser/bookmarks/bookmark_model_factory.h"
+#include "ios/chrome/browser/chrome_url_constants.h"
+#include "ios/chrome/browser/dom_distiller/dom_distiller_service_factory.h"
+#include "ios/chrome/browser/favicon/favicon_service_factory.h"
+#include "ios/chrome/browser/history/history_service_factory.h"
+#include "ios/chrome/browser/invalidation/ios_chrome_profile_invalidation_provider_factory.h"
+#include "ios/chrome/browser/passwords/ios_chrome_password_store_factory.h"
+#include "ios/chrome/browser/pref_names.h"
+#include "ios/chrome/browser/signin/oauth2_token_service_factory.h"
+#include "ios/chrome/browser/sync/glue/sync_start_util.h"
+#include "ios/chrome/browser/sync/sessions/ios_chrome_local_session_event_router.h"
+#include "ios/chrome/browser/web_data_service_factory.h"
+#include "ios/chrome/common/channel_info.h"
+#include "ios/public/provider/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
+#include "ios/public/provider/chrome/browser/keyed_service_provider.h"
+#include "ios/web/public/web_thread.h"
+#include "sync/internal_api/public/engine/passive_model_worker.h"
+#include "sync/util/extensions_activity.h"
+#include "ui/base/device_form_factor.h"
+
+namespace {
+
+// iOS implementation of SyncSessionsClient. Needs to be in a separate class
+// due to possible multiple inheritance issues, wherein IOSChromeSyncClient
+// might inherit from other interfaces with same methods.
+class SyncSessionsClientImpl : public sync_sessions::SyncSessionsClient {
+ public:
+  explicit SyncSessionsClientImpl(ios::ChromeBrowserState* browser_state)
+      : browser_state_(browser_state),
+        window_delegates_getter_(
+            ios::GetChromeBrowserProvider()
+                ->CreateSyncedWindowDelegatesGetter(browser_state)) {}
+
+  ~SyncSessionsClientImpl() override {}
+
+  // SyncSessionsClient implementation.
+  bookmarks::BookmarkModel* GetBookmarkModel() override {
+    DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+    return ios::BookmarkModelFactory::GetForBrowserState(browser_state_);
+  }
+
+  favicon::FaviconService* GetFaviconService() override {
+    DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+    return ios::FaviconServiceFactory::GetForBrowserState(
+        browser_state_, ServiceAccessType::EXPLICIT_ACCESS);
+  }
+
+  history::HistoryService* GetHistoryService() override {
+    DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+    return ios::HistoryServiceFactory::GetForBrowserState(
+        browser_state_, ServiceAccessType::EXPLICIT_ACCESS);
+  }
+
+  bool ShouldSyncURL(const GURL& url) const override {
+    if (url == GURL(kChromeUIHistoryURL)) {
+      // The history page is treated specially as we want it to trigger syncable
+      // events for UI purposes.
+      return true;
+    }
+    return url.is_valid() && !url.SchemeIs(kChromeUIScheme) &&
+           !url.SchemeIsFile();
+  }
+
+  browser_sync::SyncedWindowDelegatesGetter* GetSyncedWindowDelegatesGetter()
+      override {
+    return window_delegates_getter_.get();
+  }
+
+  scoped_ptr<browser_sync::LocalSessionEventRouter> GetLocalSessionEventRouter()
+      override {
+    syncer::SyncableService::StartSyncFlare flare(
+        ios::sync_start_util::GetFlareForSyncableService(
+            browser_state_->GetStatePath()));
+    return make_scoped_ptr(
+        new IOSChromeLocalSessionEventRouter(browser_state_, this, flare));
+  }
+
+ private:
+  ios::ChromeBrowserState* const browser_state_;
+  const scoped_ptr<browser_sync::SyncedWindowDelegatesGetter>
+      window_delegates_getter_;
+
+  DISALLOW_COPY_AND_ASSIGN(SyncSessionsClientImpl);
+};
+
+}  // namespace
+
+IOSChromeSyncClient::IOSChromeSyncClient(ios::ChromeBrowserState* browser_state)
+    : browser_state_(browser_state),
+      sync_sessions_client_(new SyncSessionsClientImpl(browser_state)),
+      dummy_extensions_activity_(new syncer::ExtensionsActivity()),
+      weak_ptr_factory_(this) {}
+
+IOSChromeSyncClient::~IOSChromeSyncClient() {}
+
+void IOSChromeSyncClient::Initialize(sync_driver::SyncService* sync_service) {
+  DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+  // Component factory may already be set in tests.
+  if (!GetSyncApiComponentFactory()) {
+    const GURL sync_service_url = GetSyncServiceURL(
+        *base::CommandLine::ForCurrentProcess(), ::GetChannel());
+    ProfileOAuth2TokenService* token_service =
+        OAuth2TokenServiceFactory::GetForBrowserState(browser_state_);
+
+    net::URLRequestContextGetter* url_request_context_getter =
+        browser_state_->GetRequestContext();
+
+    component_factory_.reset(new ProfileSyncComponentsFactoryImpl(
+        this, ::GetChannel(), ::GetVersionString(),
+        ui::GetDeviceFormFactor() == ui::DEVICE_FORM_FACTOR_TABLET,
+        *base::CommandLine::ForCurrentProcess(),
+        ios::prefs::kSavingBrowserHistoryDisabled, sync_service_url,
+        web::WebThread::GetTaskRunnerForThread(web::WebThread::UI),
+        web::WebThread::GetTaskRunnerForThread(web::WebThread::DB),
+        token_service, url_request_context_getter));
+  }
+  sync_service_ = sync_service;
+  web_data_service_ = GetWebDataService();
+  password_store_ = GetPasswordStore();
+}
+
+sync_driver::SyncService* IOSChromeSyncClient::GetSyncService() {
+  // TODO(crbug.com/558298): bring back this DCHECK after Typed URLs are
+  // converted to SyncableService.
+  // DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+  return sync_service_;
+}
+
+PrefService* IOSChromeSyncClient::GetPrefService() {
+  DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+  return browser_state_->GetPrefs();
+}
+
+bookmarks::BookmarkModel* IOSChromeSyncClient::GetBookmarkModel() {
+  DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+  return ios::BookmarkModelFactory::GetForBrowserState(browser_state_);
+}
+
+favicon::FaviconService* IOSChromeSyncClient::GetFaviconService() {
+  DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+  return ios::FaviconServiceFactory::GetForBrowserState(
+      browser_state_, ServiceAccessType::EXPLICIT_ACCESS);
+}
+
+history::HistoryService* IOSChromeSyncClient::GetHistoryService() {
+  DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+  return ios::HistoryServiceFactory::GetForBrowserState(
+      browser_state_, ServiceAccessType::EXPLICIT_ACCESS);
+}
+
+autofill::PersonalDataManager* IOSChromeSyncClient::GetPersonalDataManager() {
+  DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+  return PersonalDataManagerFactory::GetForBrowserState(browser_state_);
+}
+
+scoped_refptr<password_manager::PasswordStore>
+IOSChromeSyncClient::GetPasswordStore() {
+  DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+  // TODO(crbug.com/558320) Is EXPLICIT_ACCESS appropriate here?
+  return IOSChromePasswordStoreFactory::GetForBrowserState(
+      browser_state_, ServiceAccessType::EXPLICIT_ACCESS);
+}
+
+sync_driver::ClearBrowsingDataCallback
+IOSChromeSyncClient::GetClearBrowsingDataCallback() {
+  return base::Bind(&IOSChromeSyncClient::ClearBrowsingData,
+                    base::Unretained(this));
+}
+
+base::Closure IOSChromeSyncClient::GetPasswordStateChangedCallback() {
+  return base::Bind(
+      &IOSChromePasswordStoreFactory::OnPasswordsSyncedStatePotentiallyChanged,
+      base::Unretained(browser_state_));
+}
+
+sync_driver::SyncApiComponentFactory::RegisterDataTypesMethod
+IOSChromeSyncClient::GetRegisterPlatformTypesCallback() {
+  // The iOS port does not have any platform-specific datatypes.
+  return sync_driver::SyncApiComponentFactory::RegisterDataTypesMethod();
+}
+
+scoped_refptr<autofill::AutofillWebDataService>
+IOSChromeSyncClient::GetWebDataService() {
+  DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+  return ios::WebDataServiceFactory::GetAutofillWebDataForBrowserState(
+      browser_state_, ServiceAccessType::EXPLICIT_ACCESS);
+}
+
+BookmarkUndoService* IOSChromeSyncClient::GetBookmarkUndoServiceIfExists() {
+  // TODO(crbug.com/561569) Implement this.
+  return nullptr;
+}
+
+invalidation::InvalidationService*
+IOSChromeSyncClient::GetInvalidationService() {
+  invalidation::ProfileInvalidationProvider* provider =
+      IOSChromeProfileInvalidationProviderFactory::GetForBrowserState(
+          browser_state_);
+  if (provider)
+    return provider->GetInvalidationService();
+  return nullptr;
+}
+
+scoped_refptr<syncer::ExtensionsActivity>
+IOSChromeSyncClient::GetExtensionsActivity() {
+  // TODO(crbug.com/562048) Get rid of dummy_extensions_activity_ and return
+  // nullptr.
+  return dummy_extensions_activity_;
+}
+
+sync_sessions::SyncSessionsClient*
+IOSChromeSyncClient::GetSyncSessionsClient() {
+  return sync_sessions_client_.get();
+}
+
+base::WeakPtr<syncer::SyncableService>
+IOSChromeSyncClient::GetSyncableServiceForType(syncer::ModelType type) {
+  switch (type) {
+    case syncer::DEVICE_INFO:
+      return static_cast<ProfileSyncService*>(
+                 ios::GetKeyedServiceProvider()->GetSyncServiceForBrowserState(
+                     browser_state_))
+          ->GetDeviceInfoSyncableService()
+          ->AsWeakPtr();
+    case syncer::PREFERENCES:
+      return browser_state_->GetSyncablePrefs()
+          ->GetSyncableService(syncer::PREFERENCES)
+          ->AsWeakPtr();
+    case syncer::PRIORITY_PREFERENCES:
+      return browser_state_->GetSyncablePrefs()
+          ->GetSyncableService(syncer::PRIORITY_PREFERENCES)
+          ->AsWeakPtr();
+    case syncer::AUTOFILL:
+    case syncer::AUTOFILL_PROFILE:
+    case syncer::AUTOFILL_WALLET_DATA:
+    case syncer::AUTOFILL_WALLET_METADATA: {
+      if (!web_data_service_)
+        return base::WeakPtr<syncer::SyncableService>();
+      if (type == syncer::AUTOFILL) {
+        return autofill::AutocompleteSyncableService::FromWebDataService(
+                   web_data_service_.get())
+            ->AsWeakPtr();
+      } else if (type == syncer::AUTOFILL_PROFILE) {
+        return autofill::AutofillProfileSyncableService::FromWebDataService(
+                   web_data_service_.get())
+            ->AsWeakPtr();
+      } else if (type == syncer::AUTOFILL_WALLET_METADATA) {
+        return autofill::AutofillWalletMetadataSyncableService::
+            FromWebDataService(web_data_service_.get())
+                ->AsWeakPtr();
+      }
+      return autofill::AutofillWalletSyncableService::FromWebDataService(
+                 web_data_service_.get())
+          ->AsWeakPtr();
+    }
+    case syncer::HISTORY_DELETE_DIRECTIVES: {
+      history::HistoryService* history =
+          ios::HistoryServiceFactory::GetForBrowserState(
+              browser_state_, ServiceAccessType::EXPLICIT_ACCESS);
+      return history ? history->AsWeakPtr()
+                     : base::WeakPtr<history::HistoryService>();
+    }
+    case syncer::FAVICON_IMAGES:
+    case syncer::FAVICON_TRACKING: {
+      browser_sync::FaviconCache* favicons =
+          static_cast<ProfileSyncService*>(
+              ios::GetKeyedServiceProvider()->GetSyncServiceForBrowserState(
+                  browser_state_))
+              ->GetFaviconCache();
+      return favicons ? favicons->AsWeakPtr()
+                      : base::WeakPtr<syncer::SyncableService>();
+    }
+    case syncer::ARTICLES: {
+      dom_distiller::DomDistillerService* service =
+          dom_distiller::DomDistillerServiceFactory::GetForBrowserState(
+              browser_state_);
+      if (service)
+        return service->GetSyncableService()->AsWeakPtr();
+      return base::WeakPtr<syncer::SyncableService>();
+    }
+    case syncer::SESSIONS: {
+      return static_cast<ProfileSyncService*>(
+                 ios::GetKeyedServiceProvider()->GetSyncServiceForBrowserState(
+                     browser_state_))
+          ->GetSessionsSyncableService()
+          ->AsWeakPtr();
+    }
+    case syncer::PASSWORDS: {
+      return password_store_ ? password_store_->GetPasswordSyncableService()
+                             : base::WeakPtr<syncer::SyncableService>();
+    }
+    default:
+      // TODO(crbug.com/562170) The following datatypes still need to be
+      // transitioned to the syncer::SyncableService API:
+      // Bookmarks
+      // Typed URLs
+      NOTREACHED();
+      return base::WeakPtr<syncer::SyncableService>();
+  }
+}
+
+scoped_refptr<syncer::ModelSafeWorker>
+IOSChromeSyncClient::CreateModelWorkerForGroup(
+    syncer::ModelSafeGroup group,
+    syncer::WorkerLoopDestructionObserver* observer) {
+  DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+  switch (group) {
+    case syncer::GROUP_DB:
+      return new browser_sync::BrowserThreadModelWorker(
+          web::WebThread::GetTaskRunnerForThread(web::WebThread::DB),
+          syncer::GROUP_DB, observer);
+    case syncer::GROUP_FILE:
+      return new browser_sync::BrowserThreadModelWorker(
+          web::WebThread::GetTaskRunnerForThread(web::WebThread::FILE),
+          syncer::GROUP_FILE, observer);
+    case syncer::GROUP_UI:
+      return new browser_sync::UIModelWorker(
+          web::WebThread::GetTaskRunnerForThread(web::WebThread::UI), observer);
+    case syncer::GROUP_PASSIVE:
+      return new syncer::PassiveModelWorker(observer);
+    case syncer::GROUP_HISTORY: {
+      history::HistoryService* history_service = GetHistoryService();
+      if (!history_service)
+        return nullptr;
+      return new browser_sync::HistoryModelWorker(
+          history_service->AsWeakPtr(),
+          web::WebThread::GetTaskRunnerForThread(web::WebThread::UI), observer);
+    }
+    case syncer::GROUP_PASSWORD: {
+      scoped_refptr<password_manager::PasswordStore> password_store =
+          GetPasswordStore();
+      if (!password_store)
+        return nullptr;
+      return new browser_sync::PasswordModelWorker(password_store, observer);
+    }
+    default:
+      return nullptr;
+  }
+}
+
+sync_driver::SyncApiComponentFactory*
+IOSChromeSyncClient::GetSyncApiComponentFactory() {
+  return component_factory_.get();
+}
+
+void IOSChromeSyncClient::ClearBrowsingData(base::Time start, base::Time end) {
+  // This method should never be called on iOS.
+  NOTREACHED();
+}
+
+void IOSChromeSyncClient::SetSyncApiComponentFactoryForTesting(
+    scoped_ptr<sync_driver::SyncApiComponentFactory> component_factory) {
+  component_factory_ = component_factory.Pass();
+}
diff --git a/ios/chrome/browser/sync/ios_chrome_sync_client.h b/ios/chrome/browser/sync/ios_chrome_sync_client.h
new file mode 100644
index 0000000..a3bbcbb
--- /dev/null
+++ b/ios/chrome/browser/sync/ios_chrome_sync_client.h
@@ -0,0 +1,82 @@
+// Copyright 2015 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.
+
+#ifndef IOS_CHROME_BROWSER_SYNC_IOS_CHROME_SYNC_CLIENT_H__
+#define IOS_CHROME_BROWSER_SYNC_IOS_CHROME_SYNC_CLIENT_H__
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "components/sync_driver/sync_client.h"
+
+namespace ios {
+class ChromeBrowserState;
+}
+
+namespace sync_driver {
+class SyncApiComponentFactory;
+class SyncService;
+}
+
+class IOSChromeSyncClient : public sync_driver::SyncClient {
+ public:
+  explicit IOSChromeSyncClient(ios::ChromeBrowserState* browser_state);
+  ~IOSChromeSyncClient() override;
+
+  // SyncClient implementation.
+  void Initialize(sync_driver::SyncService* sync_service) override;
+  sync_driver::SyncService* GetSyncService() override;
+  PrefService* GetPrefService() override;
+  bookmarks::BookmarkModel* GetBookmarkModel() override;
+  favicon::FaviconService* GetFaviconService() override;
+  history::HistoryService* GetHistoryService() override;
+  scoped_refptr<password_manager::PasswordStore> GetPasswordStore() override;
+  sync_driver::ClearBrowsingDataCallback GetClearBrowsingDataCallback()
+      override;
+  base::Closure GetPasswordStateChangedCallback() override;
+  sync_driver::SyncApiComponentFactory::RegisterDataTypesMethod
+  GetRegisterPlatformTypesCallback() override;
+  autofill::PersonalDataManager* GetPersonalDataManager() override;
+  invalidation::InvalidationService* GetInvalidationService() override;
+  scoped_refptr<autofill::AutofillWebDataService> GetWebDataService() override;
+  BookmarkUndoService* GetBookmarkUndoServiceIfExists() override;
+  scoped_refptr<syncer::ExtensionsActivity> GetExtensionsActivity() override;
+  sync_sessions::SyncSessionsClient* GetSyncSessionsClient() override;
+  base::WeakPtr<syncer::SyncableService> GetSyncableServiceForType(
+      syncer::ModelType type) override;
+  scoped_refptr<syncer::ModelSafeWorker> CreateModelWorkerForGroup(
+      syncer::ModelSafeGroup group,
+      syncer::WorkerLoopDestructionObserver* observer) override;
+  sync_driver::SyncApiComponentFactory* GetSyncApiComponentFactory() override;
+
+  void SetSyncApiComponentFactoryForTesting(
+      scoped_ptr<sync_driver::SyncApiComponentFactory> component_factory);
+
+ private:
+  void ClearBrowsingData(base::Time start, base::Time end);
+
+  ios::ChromeBrowserState* const browser_state_;
+
+  // The sync api component factory in use by this client.
+  scoped_ptr<sync_driver::SyncApiComponentFactory> component_factory_;
+
+  // Members that must be fetched on the UI thread but accessed on their
+  // respective backend threads.
+  scoped_refptr<autofill::AutofillWebDataService> web_data_service_;
+  scoped_refptr<password_manager::PasswordStore> password_store_;
+
+  scoped_ptr<sync_sessions::SyncSessionsClient> sync_sessions_client_;
+
+  // TODO(crbug.com/558298): this is a member only because Typed URLs needs
+  // access to the UserShare and Cryptographer outside of the UI thread. Remove
+  // this once that's no longer the case.
+  sync_driver::SyncService* sync_service_;  // Weak.
+
+  const scoped_refptr<syncer::ExtensionsActivity> dummy_extensions_activity_;
+
+  base::WeakPtrFactory<IOSChromeSyncClient> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(IOSChromeSyncClient);
+};
+
+#endif  // IOS_CHROME_BROWSER_SYNC_IOS_CHROME_SYNC_CLIENT_H__
diff --git a/ios/chrome/ios_chrome.gyp b/ios/chrome/ios_chrome.gyp
index b77e7e6..5b6c7af 100644
--- a/ios/chrome/ios_chrome.gyp
+++ b/ios/chrome/ios_chrome.gyp
@@ -51,6 +51,8 @@
         '../../components/components.gyp:autofill_ios_browser',
         '../../components/components.gyp:bookmarks_browser',
         '../../components/components.gyp:bookmarks_managed',
+        '../../components/components.gyp:browser_sync_browser',
+        '../../components/components.gyp:browser_sync_common',
         '../../components/components.gyp:component_updater',
         '../../components/components.gyp:content_settings_core_browser',
         '../../components/components.gyp:crash_core_browser',
@@ -453,6 +455,8 @@
         'browser/suggestions/suggestions_service_factory.mm',
         'browser/sync/glue/sync_start_util.cc',
         'browser/sync/glue/sync_start_util.h',
+        'browser/sync/ios_chrome_sync_client.cc',
+        'browser/sync/ios_chrome_sync_client.h',
         'browser/sync/ios_chrome_synced_tab_delegate.cc',
         'browser/sync/ios_chrome_synced_tab_delegate.h',
         'browser/sync/sessions/ios_chrome_local_session_event_router.cc',
diff --git a/ios/public/provider/chrome/browser/chrome_browser_provider.cc b/ios/public/provider/chrome/browser/chrome_browser_provider.cc
index 9435b17..a12824c 100644
--- a/ios/public/provider/chrome/browser/chrome_browser_provider.cc
+++ b/ios/public/provider/chrome/browser/chrome_browser_provider.cc
@@ -9,9 +9,9 @@
 #include "base/logging.h"
 #include "components/metrics/metrics_provider.h"
 #include "components/sync_sessions/local_session_event_router.h"
+#include "components/sync_sessions/synced_window_delegates_getter.h"
 #include "ios/public/provider/chrome/browser/browsing_data/ios_chrome_browsing_data_remover_provider.h"
 #include "ios/public/provider/chrome/browser/keyed_service_provider.h"
-#include "ios/public/provider/chrome/browser/keyed_service_provider.h"
 
 namespace ios {
 
@@ -132,4 +132,10 @@ bool ChromeBrowserProvider::IsSafeBrowsingEnabled(
 
 void ChromeBrowserProvider::OnMetricsServicesManagerClientDestroyed() {}
 
+scoped_ptr<browser_sync::SyncedWindowDelegatesGetter>
+ChromeBrowserProvider::CreateSyncedWindowDelegatesGetter(
+    ios::ChromeBrowserState* browser_state) {
+  return nullptr;
+}
+
 }  // namespace ios
diff --git a/ios/public/provider/chrome/browser/chrome_browser_provider.h b/ios/public/provider/chrome/browser/chrome_browser_provider.h
index a557d91..470b3e4 100644
--- a/ios/public/provider/chrome/browser/chrome_browser_provider.h
+++ b/ios/public/provider/chrome/browser/chrome_browser_provider.h
@@ -11,6 +11,7 @@
 #include <vector>
 
 #include "base/callback_forward.h"
+#include "base/memory/scoped_ptr.h"
 #include "components/favicon_base/favicon_callback.h"
 
 class AutocompleteProvider;
@@ -25,6 +26,10 @@ class CardUnmaskPromptController;
 class CardUnmaskPromptView;
 }
 
+namespace browser_sync {
+class SyncedWindowDelegatesGetter;
+}
+
 namespace net {
 class URLRequestContextGetter;
 }
@@ -130,6 +135,10 @@ class ChromeBrowserProvider {
   // Called when the IOSChromeMetricsServiceClientManager instance is
   // destroyed.
   virtual void OnMetricsServicesManagerClientDestroyed();
+
+  // Returns the SyncedWindowDelegatesGetter implementation.
+  virtual scoped_ptr<browser_sync::SyncedWindowDelegatesGetter>
+  CreateSyncedWindowDelegatesGetter(ios::ChromeBrowserState* browser_state);
 };
 
 }  // namespace ios