[Sync] Convert DTCs to be not RefCounted and NonThreadSafe.

components/sync/driver/proxy_data_type_controller.h

Index: components/sync/driver/proxy_data_type_controller.h
diff --git a/components/sync/driver/proxy_data_type_controller.h b/components/sync/driver/proxy_data_type_controller.h
index 186400bd67be3073931c5d0179f5e26cf74157a8..5d04f980bad96740cc3076b36e8813790a68566e 100644
--- a/components/sync/driver/proxy_data_type_controller.h
+++ b/components/sync/driver/proxy_data_type_controller.h
@@ -5,6 +5,7 @@
 #ifndef COMPONENTS_SYNC_DRIVER_PROXY_DATA_TYPE_CONTROLLER_H__
 #define COMPONENTS_SYNC_DRIVER_PROXY_DATA_TYPE_CONTROLLER_H__
 
+#include <memory>
 #include <string>
 
 #include "base/compiler_specific.h"
@@ -19,9 +20,8 @@ namespace sync_driver {
 // service.
 class ProxyDataTypeController : public DataTypeController {
  public:
-  explicit ProxyDataTypeController(
-      const scoped_refptr<base::SingleThreadTaskRunner>& ui_thread,
-      syncer::ModelType type);
+  explicit ProxyDataTypeController(syncer::ModelType type);
+  ~ProxyDataTypeController() override;
 
   // DataTypeController interface.
   bool ShouldLoadModelBeforeConfigure() const override;
@@ -29,27 +29,18 @@ class ProxyDataTypeController : public DataTypeController {
   void RegisterWithBackend(BackendDataTypeConfigurer* configurer) override;
   void StartAssociating(const StartCallback& start_callback) override;
   void Stop() override;
-  syncer::ModelType type() const override;
   std::string name() const override;
   State state() const override;
   void ActivateDataType(BackendDataTypeConfigurer* configurer) override;
   void DeactivateDataType(BackendDataTypeConfigurer* configurer) override;
   void GetAllNodes(const AllNodesCallback& callback) override;
 
-  // DataTypeErrorHandler interface.
-  void OnSingleDataTypeUnrecoverableError(
-      const syncer::SyncError& error) override;
-
  protected:
-  // DataTypeController is RefCounted.
-  ~ProxyDataTypeController() override;
+  std::unique_ptr<syncer::DataTypeErrorHandler> CreateErrorHandler() override;
 
  private:
   State state_;
 
-  // The actual type for this controller.
-  syncer::ModelType type_;
-
   DISALLOW_COPY_AND_ASSIGN(ProxyDataTypeController);
 };