[Sync] Add support for enabling session sync remotely.

chrome/browser/sync/profile_sync_factory.h

 // Copyright (c) 2011 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 CHROME_BROWSER_SYNC_PROFILE_SYNC_FACTORY_H__
 #define CHROME_BROWSER_SYNC_PROFILE_SYNC_FACTORY_H__
 #pragma once
 
 #include <string>
 #include <utility>
@@ skipping 43 matching lines @@
 
   // Creates and registers enabled datatypes with the provided
   // ProfileSyncService.
   virtual void RegisterDataTypes(ProfileSyncService* pss) = 0;
 
   // Instantiates a new DataTypeManager with a SyncBackendHost and a
   // list of data type controllers.  The return pointer is owned by
   // the caller.
   virtual browser_sync::DataTypeManager* CreateDataTypeManager(
       browser_sync::SyncBackendHost* backend,
-      const browser_sync::DataTypeController::TypeMap& controllers) = 0;
+      const browser_sync::DataTypeController::TypeMap* controllers) = 0;
 
   // Instantiates both a model associator and change processor for the
   // app data type.  The pointers in the return struct are
   // owned by the caller.
   virtual SyncComponents CreateAppSyncComponents(
       ProfileSyncService* profile_sync_service,
       browser_sync::UnrecoverableErrorHandler* error_handler) = 0;
 
   // Instantiates both a model associator and change processor for the
   // autofill data type.  The pointers in the return struct are owned
@@ skipping 59 matching lines @@
 
   // Instantiates both a model associator and change processor for the
   // session data type.  The pointers in the return struct are
   // owned by the caller.
   virtual SyncComponents CreateSessionSyncComponents(
       ProfileSyncService* profile_sync_service,
       browser_sync::UnrecoverableErrorHandler* error_handler) = 0;
 };
 
 #endif  // CHROME_BROWSER_SYNC_PROFILE_SYNC_FACTORY_H__