Revert of [Sync] Make directory types registration explicit in ModelTypeRegistry

components/sync/engine/sync_manager.h

Index: components/sync/engine/sync_manager.h
diff --git a/components/sync/engine/sync_manager.h b/components/sync/engine/sync_manager.h
index b853b542717b6f54d1d190b10347277e5e301ba9..37e7de633eca0dd9d13d58b571cc697c6a7378d0 100644
--- a/components/sync/engine/sync_manager.h
+++ b/components/sync/engine/sync_manager.h
@@ -304,11 +304,8 @@
   virtual void UpdateCredentials(const SyncCredentials& credentials) = 0;
 
   // Put the syncer in normal mode ready to perform nudges and polls.
-  virtual void StartSyncingNormally(base::Time last_poll_time) = 0;
-
-  // Put syncer in configuration mode. Only configuration sync cycles are
-  // performed. No local changes are committed to the server.
-  virtual void StartConfiguration() = 0;
+  virtual void StartSyncingNormally(const ModelSafeRoutingInfo& routing_info,
+                                    base::Time last_poll_time) = 0;
 
   // Switches the mode of operation to CONFIGURATION_MODE and performs
   // any configuration tasks needed as determined by the params. Once complete,
@@ -320,6 +317,7 @@
   //              does finish.
   virtual void ConfigureSyncer(ConfigureReason reason,
                                ModelTypeSet to_download,
+                               const ModelSafeRoutingInfo& new_routing_info,
                                const base::Closure& ready_task,
                                const base::Closure& retry_task) = 0;
 
@@ -354,13 +352,7 @@
   // May be called from any thread.
   virtual UserShare* GetUserShare() = 0;
 
-  // Returns non-owning pointer to ModelTypeConnector. In contrast with
-  // ModelTypeConnectorProxy all calls are executed synchronously, thus the
-  // pointer should be used on sync thread.
-  virtual ModelTypeConnector* GetModelTypeConnector() = 0;
-
-  // Returns an instance of the main interface for registering sync types with
-  // sync engine.
+  // Returns an instance of the main interface for non-blocking sync types.
   virtual std::unique_ptr<ModelTypeConnector> GetModelTypeConnectorProxy() = 0;
 
   // Returns the cache_guid of the currently open database.