[Sync] SyncEngine refactor part 2: SyncServiceBase.

components/sync/engine/sync_engine.h

 // Copyright 2012 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 COMPONENTS_SYNC_ENGINE_SYNC_ENGINE_H_
 #define COMPONENTS_SYNC_ENGINE_SYNC_ENGINE_H_
 
+#include <map>
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
+#include "base/files/file_path.h"
 #include "base/macros.h"
+#include "base/memory/ref_counted.h"
 #include "base/single_thread_task_runner.h"
+#include "components/sync/base/extensions_activity.h"
 #include "components/sync/base/model_type.h"
 #include "components/sync/base/weak_handle.h"
 #include "components/sync/engine/configure_reason.h"
 #include "components/sync/engine/cycle/sync_cycle_snapshot.h"
 #include "components/sync/engine/model_type_configurer.h"
 #include "components/sync/engine/shutdown_reason.h"
+#include "components/sync/engine/sync_backend_registrar.h"
 #include "components/sync/engine/sync_manager.h"
 #include "components/sync/engine/sync_manager_factory.h"
 
 class GURL;
 
 namespace syncer {
 
 class CancelationSignal;
 class HttpPostProviderFactory;
 class SyncEngineHost;
 class SyncManagerFactory;
 class UnrecoverableErrorHandler;
 
 // The interface into the sync engine, which is the part of sync that performs
 // communication between model types and the sync server. In prod the engine
 // will always live on the sync thread and the object implementing this
 // interface will handle crossing threads if necessary.
 class SyncEngine : public ModelTypeConfigurer {
  public:
   typedef SyncStatus Status;
   typedef base::Callback<std::unique_ptr<HttpPostProviderFactory>(
       CancelationSignal*)>
       HttpPostProviderFactoryGetter;
 
-  // Stubs used by implementing classes.
+  // Utility struct for holding initialization options.
+  struct InitParams {
+    InitParams();
+    InitParams(InitParams&& other);
+    ~InitParams();
+
+    scoped_refptr<base::SingleThreadTaskRunner> sync_task_runner;
+    SyncEngineHost* host = nullptr;
+    std::unique_ptr<SyncBackendRegistrar> registrar;
+    scoped_refptr<ExtensionsActivity> extensions_activity;
+    WeakHandle<JsEventHandler> event_handler;
+    GURL service_url;
+    std::string sync_user_agent;
+    SyncEngine::HttpPostProviderFactoryGetter http_factory_getter;
+    SyncCredentials credentials;
+    std::string invalidator_client_id;
+    std::unique_ptr<SyncManagerFactory> sync_manager_factory;
+    bool delete_sync_data_folder = false;
+    bool enable_local_sync_backend = false;
+    base::FilePath local_sync_backend_folder;
+    std::string restored_key_for_bootstrapping;
+    std::string restored_keystore_key_for_bootstrapping;
+    std::unique_ptr<EngineComponentsFactory> engine_components_factory;
+    WeakHandle<UnrecoverableErrorHandler> unrecoverable_error_handler;
+    base::Closure report_unrecoverable_error_function;
+    std::unique_ptr<SyncEncryptionHandler::NigoriState> saved_nigori_state;
+    std::map<ModelType, int64_t> invalidation_versions;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(InitParams);
+  };
+
   SyncEngine();
   ~SyncEngine() override;
 
   // Kicks off asynchronous initialization. Optionally deletes sync data during
   // init in order to make sure we're starting fresh.
   //
   // |saved_nigori_state| is optional nigori state to restore from a previous
   // engine instance. May be null.
-  virtual void Initialize(
-      SyncEngineHost* host,
-      scoped_refptr<base::SingleThreadTaskRunner> sync_task_runner,
-      const WeakHandle<JsEventHandler>& event_handler,
-      const GURL& service_url,
-      const std::string& sync_user_agent,
-      const SyncCredentials& credentials,
-      bool delete_sync_data_folder,
-      bool enable_local_sync_backend,
-      const base::FilePath& local_sync_backend_folder,
-      std::unique_ptr<SyncManagerFactory> sync_manager_factory,
-      const WeakHandle<UnrecoverableErrorHandler>& unrecoverable_error_handler,
-      const base::Closure& report_unrecoverable_error_function,
-      const HttpPostProviderFactoryGetter& http_post_provider_factory_getter,
-      std::unique_ptr<SyncEncryptionHandler::NigoriState>
-          saved_nigori_state) = 0;
+  virtual void Initialize(InitParams params) = 0;
 
   // Inform the engine to trigger a sync cycle for |types|.
   virtual void TriggerRefresh(const ModelTypeSet& types) = 0;
 
   // Updates the engine's SyncCredentials.
   virtual void UpdateCredentials(const SyncCredentials& credentials) = 0;
 
   // This starts the sync engine running a Syncer object to communicate with
   // sync servers. Until this is called, no changes will leave or enter this
   // browser from the cloud / sync servers.
@@ skipping 114 matching lines @@
   // See SyncManager::OnCookieJarChanged.
   virtual void OnCookieJarChanged(bool account_mismatch, bool empty_jar) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SyncEngine);
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_ENGINE_SYNC_ENGINE_H_