[Sync] ModelTypeStore factory shouldn't require valid PSS to function correctly

components/browser_sync/profile_sync_service.h

 // Copyright (c) 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_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_
 #define COMPONENTS_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_
 
 #include <memory>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/memory_pressure_listener.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/observer_list.h"
 #include "base/strings/string16.h"
+#include "base/threading/sequenced_worker_pool.h"
 #include "base/threading/thread.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "build/build_config.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/signin/core/browser/gaia_cookie_manager_service.h"
 #include "components/signin/core/browser/signin_manager_base.h"
 #include "components/sync/base/experiments.h"
 #include "components/sync/base/model_type.h"
 #include "components/sync/base/sync_prefs.h"
@@ skipping 16 matching lines @@
 #include "components/sync/engine/sync_manager_factory.h"
 #include "components/sync/js/sync_js_controller.h"
 #include "components/sync/model/model_type_store.h"
 #include "components/sync/syncable/user_share.h"
 #include "components/version_info/version_info.h"
 #include "google_apis/gaia/google_service_auth_error.h"
 #include "google_apis/gaia/oauth2_token_service.h"
 #include "net/base/backoff_entry.h"
 #include "url/gurl.h"
 
-class Profile;
 class ProfileOAuth2TokenService;
 class SigninManagerWrapper;
 
 namespace sync_sessions {
 class FaviconCache;
 class OpenTabsUIDelegate;
 class SessionsSyncManager;
 }  // namespace sync_sessions
 
 namespace syncer {
@@ skipping 163 matching lines @@
     std::unique_ptr<syncer::SyncClient> sync_client;
     std::unique_ptr<SigninManagerWrapper> signin_wrapper;
     ProfileOAuth2TokenService* oauth2_token_service = nullptr;
     GaiaCookieManagerService* gaia_cookie_manager_service = nullptr;
     StartBehavior start_behavior = MANUAL_START;
     syncer::NetworkTimeUpdateCallback network_time_update_callback;
     base::FilePath base_directory;
     scoped_refptr<net::URLRequestContextGetter> url_request_context;
     std::string debug_identifier;
     version_info::Channel channel = version_info::Channel::UNKNOWN;
-    scoped_refptr<base::SequencedTaskRunner> blocking_task_runner;
 
    private:
     DISALLOW_COPY_AND_ASSIGN(InitParams);
   };
 
   explicit ProfileSyncService(InitParams init_params);
 
   ~ProfileSyncService() override;
 
   // Initializes the object. This must be called at most once, and
@@ skipping 291 matching lines @@
 
   // Returns a serialized NigoriKey proto generated from the bootstrap token in
   // SyncPrefs. Will return the empty string if no bootstrap token exists.
   std::string GetCustomPassphraseKey() const;
 
   // Set the provider for whether sync is currently allowed by the platform.
   void SetPlatformSyncAllowedProvider(
       const PlatformSyncAllowedProvider& platform_sync_allowed_provider);
 
   // Returns a function for |type| that will create a ModelTypeStore that shares
-  // the sync LevelDB backend.
-  syncer::ModelTypeStoreFactory GetModelTypeStoreFactory(
-      syncer::ModelType type);
+  // the sync LevelDB backend. |base_path| should be set to profile path.
+  // |sequenced_worker_pool| is obtained from content::BrowserThread or
+  // web::WebThread depending on platform.
+  static syncer::ModelTypeStoreFactory GetModelTypeStoreFactory(
+      syncer::ModelType type,
+      const base::FilePath& base_path,
+      base::SequencedWorkerPool* sequenced_worker_pool);
 
   // Needed to test whether the directory is deleted properly.
   base::FilePath GetDirectoryPathForTest() const;
 
   // Sometimes we need to wait for tasks on the sync thread in tests.
   base::MessageLoop* GetSyncLoopForTest() const;
 
   // Some tests rely on injecting calls to the encryption observer.
   syncer::SyncEncryptionHandler::Observer* GetEncryptionObserverForTest() const;
 
@@ skipping 184 matching lines @@
   // OnConfigureStart has not yet been called, and is reset to zero once
   // OnConfigureDone is called.
   base::Time sync_configure_start_time_;
 
   // Callback to update the network time; used for initializing the engine.
   syncer::NetworkTimeUpdateCallback network_time_update_callback_;
 
   // The request context in which sync should operate.
   scoped_refptr<net::URLRequestContextGetter> url_request_context_;
 
-  // The task runner to use for blocking IO operations.
-  scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
-
   // Indicates if this is the first time sync is being configured.  This value
   // is equal to !IsFirstSetupComplete() at the time of OnEngineInitialized().
   bool is_first_time_sync_configure_;
 
   // Number of UIs currently configuring the Sync service. When this number
   // is decremented back to zero, Sync setup is marked no longer in progress.
   int outstanding_setup_in_progress_handles_ = 0;
 
   // List of available data type controllers.
   syncer::DataTypeController::TypeMap data_type_controllers_;
@@ skipping 113 matching lines @@
   base::WeakPtrFactory<ProfileSyncService> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileSyncService);
 };
 
 bool ShouldShowActionOnUI(const syncer::SyncProtocolError& error);
 
 }  // namespace browser_sync
 
 #endif  // COMPONENTS_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_