[Sync] Allow sync start without sign-in if the local sync backend is on.

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>
@@ skipping 228 matching lines @@
     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;
     base::SequencedWorkerPool* blocking_pool = nullptr;
+    bool local_sync_backend_enabled = false;
+    base::FilePath local_sync_backend_folder;
 
    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 583 matching lines @@
 
   // Set when sync receives DISABLED_BY_ADMIN error from server. Prevents
   // ProfileSyncService from starting backend till browser restarted or user
   // signed out.
   bool sync_disabled_by_admin_;
 
   // Set to true if a signin has completed but we're still waiting for the
   // backend to refresh its credentials.
   bool is_auth_in_progress_;
 
+  // Set to true when sync should use a local sync backend to store its data.
+  bool local_sync_backend_enabled_;
+
+  // The location where the local sync backend stores its data.
+  base::FilePath local_sync_backend_folder_;
+
   // Encapsulates user signin - used to set/get the user's authenticated
   // email address.
   const std::unique_ptr<SigninManagerWrapper> signin_;
 
   // Information describing an unrecoverable error.
   UnrecoverableErrorReason unrecoverable_error_reason_;
   std::string unrecoverable_error_message_;
   tracked_objects::Location unrecoverable_error_location_;
 
   // Manages the start and stop of the data types.
@@ skipping 141 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_