[Sync] Have configuration specify which datatypes are ready to sync

chrome/browser/sync/glue/sync_backend_host_mock.h

 // Copyright 2013 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_GLUE_SYNC_BACKEND_HOST_MOCK_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_MOCK_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 35 matching lines @@
                                bool is_explicit) override;
 
   bool SetDecryptionPassphrase(const std::string& passphrase) override;
 
   void StopSyncingForShutdown() override;
 
   scoped_ptr<base::Thread> Shutdown(syncer::ShutdownReason reason) override;
 
   void UnregisterInvalidationIds() override;
 
-  void ConfigureDataTypes(
+  syncer::ModelTypeSet ConfigureDataTypes(
       syncer::ConfigureReason reason,
       const DataTypeConfigStateMap& config_state_map,
       const base::Callback<void(syncer::ModelTypeSet, syncer::ModelTypeSet)>&
           ready_task,
       const base::Callback<void()>& retry_callback) override;
 
   void EnableEncryptEverything() override;
 
   void ActivateDataType(
       syncer::ModelType type,
@@ skipping 40 matching lines @@
 
   void set_fail_initial_download(bool should_fail);
 
  private:
   bool fail_initial_download_;
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_MOCK_H_